Reference / Curriculum / 3B / Complete worked solutions

Semester 3B · Original public practice · Internally reviewed; external trial pending

Complete worked solutions

Detailed explanations for the cumulative review and practice examination.

Complete worked solutions for all original Semester 3B review and exam questions. Keep this page separate while students attempt the exam.

Exam marking guide

Review answer key

  1. 3B-REVIEW-001 · 48

    5 × 8 = 40. One additional group contains 8, giving 40 + 8 = 48.

    Related competency: MATH-3B-C08-L01

  2. 3B-REVIEW-002 · 42

    (5 × 6) + (2 × 6) = 30 + 12 = 42. Both parts represent all seven groups.

    Related competency: MATH-3B-C08-L02

  3. 3B-REVIEW-003 · 54

    6 × (10 − 1) = 60 − 6 = 54; or (5 × 9) + 9 = 45 + 9 = 54. Both partition the same groups.

    Related competency: MATH-3B-C08-L03

  4. 3B-REVIEW-004 · 12

    Because 7 × 12 = 84, each group contains 84 ÷ 7 = 12.

    Related competency: MATH-3B-C08-L04

  5. 3B-REVIEW-005 · 56

    4 × 7 = 28. Doubling the number of groups doubles the total: 28 + 28 = 56.

    Related competency: MATH-3B-C08-L06

  6. 3B-REVIEW-006 · 72

    10 × 8 = 80. Remove one group of 8: 80 − 8 = 72.

    Related competency: MATH-3B-C08-L07

  7. 3B-REVIEW-007 · 72 books

    Eight equal groups of nine give 8 × 9 = 72 books. An 8-by-9 array has the same 72 cells.

    Related competency: MATH-3B-C08-L08

  8. 3B-REVIEW-008 · 9 full boxes; 3 pencils remain

    8 × 9 = 72, and 75 − 72 = 3. The remainder 3 is less than 8.

    Related competency: MATH-3B-C08-L09

  9. 3B-REVIEW-009 · 3/8

    The whole has eight equal parts, so the denominator is 8; three are shaded, so the numerator is 3.

    Related competency: MATH-3B-C09-L01

  10. 3B-REVIEW-010 · 3/5

    Each step is 1/5 of the unit interval; three equal steps from zero reach 3/5.

    Related competency: MATH-3B-C09-L02

  11. 3B-REVIEW-011 · 5/9 < 7/9

    Both fractions refer to ninths of the same-sized whole, and five ninths is less than seven ninths.

    Related competency: MATH-3B-C09-L03

  12. 3B-REVIEW-012 · 3/5

    If the whole is the same size, fifths are larger pieces than eighths. Three larger fifth-pieces make more than three eighth-pieces.

    Related competency: MATH-3B-C09-L04

  13. 3B-REVIEW-013 · 3 cells; 3/6

    Half of six equal cells is three cells. Thus 1/2 and 3/6 describe the same portion of the same whole.

    Related competency: MATH-3B-C10-L01

  14. 3B-REVIEW-014 · 9/12

    Multiply the denominator by 3, so also multiply the numerator by 3: 3 × 3 = 9. Same amount, smaller named parts.

    Related competency: MATH-3B-C10-L02

  15. 3B-REVIEW-015 · 2/3

    Divide numerator and denominator by 6: 12 ÷ 6 = 2 and 18 ÷ 6 = 3. No common factor greater than 1 remains.

    Related competency: MATH-3B-C10-L03

  16. 3B-REVIEW-016 · 3/4 > 5/8

    3/4 = 6/8. Six eighths is greater than five eighths.

    Related competency: MATH-3B-C10-L04

  17. 3B-REVIEW-017 · 5/6 > 7/9

    5/6 = 15/18 and 7/9 = 14/18. Therefore 5/6 is larger by 1/18.

    Related competency: MATH-3B-C10-L05

  18. 3B-REVIEW-018 · 4/5

    3 tenths + 5 tenths = 8/10. Divide top and bottom by 2 to get 4/5.

    Related competency: MATH-3B-C10-L07

  19. 3B-REVIEW-019 · 3/4

    Rename 1/2 as 2/4, then 2/4 + 1/4 = 3/4. The whole is divided consistently into fourths.

    Related competency: MATH-3B-C10-L08

  20. 3B-REVIEW-020 · 435 cm

    Four meters is 4×100 = 400 cm. Add 35 cm to get 435 cm.

    Related competency: MATH-3B-C11-L01

  21. 3B-REVIEW-021 · 4 m 37 cm

    Exchange one meter for 100 cm: 5 m 12 cm = 4 m 112 cm. Subtract 75 cm to leave 4 m 37 cm.

    Related competency: MATH-3B-C11-L02

  22. 3B-REVIEW-022 · 3,450 m

    One kilometer is 1,000 m; 3,000 m + 450 m = 3,450 m.

    Related competency: MATH-3B-C11-L03

  23. 3B-REVIEW-023 · 5 km 255 m

    Regroup 6 km 40 m as 5 km 1,040 m. Then 1,040−785=255 m, giving 5 km 255 m.

    Related competency: MATH-3B-C11-L04

  24. 3B-REVIEW-024 · 2,350 mL

    2 liters = 2,000 mL; add 350 mL to obtain 2,350 mL.

    Related competency: MATH-3B-C11-L05

  25. 3B-REVIEW-025 · 4,090 g

    Four kilograms = 4,000 g, and 4,000 + 90 = 4,090 g.

    Related competency: MATH-3B-C11-L06

  26. 3B-REVIEW-026 · 2 L 350 mL

    3,200 mL − 850 mL = 2,350 mL = 2 L 350 mL. Convert to one unit before subtracting.

    Related competency: MATH-3B-C11-L07

  27. 3B-REVIEW-027 · 10 cm

    A diameter passes through the center between two boundary points, so it is twice the radius: 2×5=10 cm.

    Related competency: MATH-3B-C12-L01

  28. 3B-REVIEW-028 · Smaller (acute)

    A right angle is 90°, and 65° < 90°. Ray length does not affect angle size.

    Related competency: MATH-3B-C12-L02

  29. 3B-REVIEW-029 · Acute; right; obtuse

    35° is less than 90°, 90° is exactly a right angle, and 130° is between 90° and 180°.

    Related competency: MATH-3B-C12-L03

  30. 3B-REVIEW-030 · Isosceles triangle

    Exactly two lengths match (6 and 6), so the triangle is isosceles; the third side is different.

    Related competency: MATH-3B-C12-L04

  31. 3B-REVIEW-031 · True under that inclusive definition

    An equilateral triangle has three equal sides, so it certainly has at least two equal sides. Naming conventions may distinguish “exactly two” in some classrooms.

    Related competency: MATH-3B-C12-L05

  32. 3B-REVIEW-032 · Yes

    A rectangle has four right angles. A square has four right angles and four equal sides, so it satisfies the rectangle definition.

    Related competency: MATH-3B-C12-L06

  33. 3B-REVIEW-033 · A circle centered at O, with a labeled 3 cm radius

    Keep the compass point fixed at O and its opening at 3 cm. Every boundary point is 3 cm from O. Label one segment from O to the boundary as 3 cm.

    Related competency: MATH-3B-C12-L07

  34. 3B-REVIEW-034 · 20 square units

    Each of 5 rows contains 4 tiles; 5×4=20 equal square units cover the region without gaps.

    Related competency: MATH-3B-C13-L01

  35. 3B-REVIEW-035 · 18 cm²

    3×6=18 tiles, each measuring 1 square centimeter. Area is 18 cm², not 18 cm.

    Related competency: MATH-3B-C13-L02

  36. 3B-REVIEW-036 · 36 cm²

    Nine columns of four square centimeters, or 9×4, give 36 cm².

    Related competency: MATH-3B-C13-L03

  37. 3B-REVIEW-037 · 42 square units

    Outer area 8×6 = 48. Remove the missing area 3×2 = 6. Result 48−6=42 square units.

    Related competency: MATH-3B-C13-L04

  38. 3B-REVIEW-038 · 16 cm

    Perimeter adds the outside edges: 5+3+5+3 = 16 cm. It is a length.

    Related competency: MATH-3B-C13-L06

  39. 3B-REVIEW-039 · 36 m

    Perimeter = 2(11+7) = 2×18 = 36 m, adding all four sides.

    Related competency: MATH-3B-C13-L07

  40. 3B-REVIEW-040 · Same area 24; perimeters 22 and 20

    Areas: 3×8=24 and 4×6=24. Perimeters: 2(3+8)=22 and 2(4+6)=20. Equal area need not give equal perimeter.

    Related competency: MATH-3B-C13-L08

  41. 3B-REVIEW-041 · 205 seconds

    Three minutes is 3×60=180 seconds; add 25 to obtain 205 seconds.

    Related competency: MATH-3B-C14-L01

  42. 3B-REVIEW-042 · 45 minutes

    From 9:20 to 10:00 is 40 min; from 10:00 to 10:05 is 5 min; total 45 min.

    Related competency: MATH-3B-C14-L02

  43. 3B-REVIEW-043 · 5:50 p.m.

    Add one hour to 5:15 p.m., then 35 minutes to 5:50 p.m.

    Related competency: MATH-3B-C14-L04

  44. 3B-REVIEW-044 · 40 minutes

    11:50 a.m. to noon is 10 min, and noon to 12:30 p.m. is 30 min. Total 40 min.

    Related competency: MATH-3B-C14-L05

  45. 3B-REVIEW-045 · 65 minutes (1 hour 5 minutes)

    The complete schedule includes both reading periods and the rest: 25+10+30=65 minutes.

    Related competency: MATH-3B-C14-L06

  46. 3B-REVIEW-046 · $4.07

    There are 100 cents in a dollar. Seven cents is 07 in the two cent places, so $4.07 rather than $4.70.

    Related competency: MATH-3B-C15-L01

  47. 3B-REVIEW-047 · $3.15

    $6.85→$7.00 adds $0.15; $7.00→$10.00 adds $3.00, so total $3.15.

    Related competency: MATH-3B-C15-L02

  48. 3B-REVIEW-048 · $16.23

    48 cents + 75 cents = 123 cents = $1.23. Dollars 12+3+1=16; total $16.23.

    Related competency: MATH-3B-C15-L03

  49. 3B-REVIEW-049 · $12.14

    Rename $20.00 as $19 and 100 cents. 100−86=14 cents, 19−7=12 dollars, giving $12.14.

    Related competency: MATH-3B-C15-L04

  50. 3B-REVIEW-050 · $23.80

    Total spent $13.45+$2.75=$16.20. Subtract $40.00−$16.20=$23.80.

    Related competency: MATH-3B-C15-L05

  51. 3B-REVIEW-051 · 50

    The eight rows hold 8×7=56 seats in total. Six seats are empty, so 56−6=50 people are seated.

    Related competency: MATH-3B-C08-L06, MATH-3B-C08-L08

  52. 3B-REVIEW-052 · 108

    10×12=120; remove one twelve: 120−12=108.

    Related competency: MATH-3B-C08-L07

  53. 3B-REVIEW-053 · 10 groups and 3 extra

    83 = 8×10 + 3; the remainder is less than 8.

    Related competency: MATH-3B-C08-L09

  54. 3B-REVIEW-054 · 6/10

    Six of ten same-sized parts is six tenths; unequal pieces would not each be one tenth.

    Related competency: MATH-3B-C09-L01

  55. 3B-REVIEW-055 · 4/7 > 4/9

    Sevenths are larger pieces than ninths, and both amounts have four pieces.

    Related competency: MATH-3B-C09-L04

  56. 3B-REVIEW-056 · Ninth tick; by 5/12

    Positions are 4/12 and 9/12. Subtract 9/12−4/12=5/12 of the unit.

    Related competency: MATH-3B-C09-L02, MATH-3B-C09-L03

  57. 3B-REVIEW-057 · 5/6

    Five of six equal parts are shaded. Five and six share no factor >1.

    Related competency: MATH-3B-C10-L07

  58. 3B-REVIEW-058 · 3/8

    One whole is 8/8. The missing part is 8/8−5/8 = 3/8, because the two amounts must combine to a whole.

    Related competency: MATH-3B-C10-L07

  59. 3B-REVIEW-059 · 5/6

    The parts need a common size: 2/3 = 4/6. Then 4/6+1/6=5/6. Adding denominators is invalid.

    Related competency: MATH-3B-C10-L08

  60. 3B-REVIEW-060 · 4 L 400 mL

    First convert 5 L 150 mL to 5,150 mL. Subtract 750 mL to get 4,400 mL, which is 4 L 400 mL.

    Related competency: MATH-3B-C11-L05, MATH-3B-C11-L07

  61. 3B-REVIEW-061 · 1 kg 225 g

    Convert both to grams: 3 kg 25 g = 3,025 g and 1 kg 800 g = 1,800 g. Their difference is 1,225 g = 1 kg 225 g.

    Related competency: MATH-3B-C11-L06

  62. 3B-REVIEW-062 · 3,430 m

    First distance is 2,080 m. Add 2,080+1,350=3,430 m.

    Related competency: MATH-3B-C11-L03, MATH-3B-C11-L07

  63. 3B-REVIEW-063 · Square

    A square satisfies both the rectangle condition (four right angles) and rhombus condition (four equal sides).

    Related competency: MATH-3B-C12-L06

  64. 3B-REVIEW-064 · Scalene

    All three side lengths differ, so it is scalene. The lengths also satisfy the triangle inequality, since 5+7>9.

    Related competency: MATH-3B-C12-L04

  65. 3B-REVIEW-065 · 8 cm

    That segment is a diameter, twice the 4 cm radius: 8 cm.

    Related competency: MATH-3B-C12-L01, MATH-3B-C12-L07

  66. 3B-REVIEW-066 · 40 m² and 26 m

    Area=8×5=40 m². Perimeter=2(8+5)=26 m.

    Related competency: MATH-3B-C13-L03, MATH-3B-C13-L07

  67. 3B-REVIEW-067 · 30 square units

    Whole 9×4=36. Corner cutout 2×3=6. Remaining area=36−6=30.

    Related competency: MATH-3B-C13-L04

  68. 3B-REVIEW-068 · Areas 25 and 27; perimeters 20 and 24

    5×5=25; 3×9=27. Perimeters are 4×5=20 and 2(3+9)=24.

    Related competency: MATH-3B-C13-L08

  69. 3B-REVIEW-069 · 12:15 p.m.

    80 minutes is 1 h 20 min. 10:55 a.m. + 1 h =11:55 a.m.; +20 min reaches 12:15 p.m.

    Related competency: MATH-3B-C14-L04, MATH-3B-C14-L05

  70. 3B-REVIEW-070 · 54 hours

    Each day is 24 hours, so two days = 48 hours. Add another 6 hours: 48+6 = 54 hours.

    Related competency: MATH-3B-C14-L01

  71. 3B-REVIEW-071 · 4:45 p.m.

    35+10+20=65 minutes = 1 h 5 min. Start 3:40 p.m., finish 4:45 p.m.

    Related competency: MATH-3B-C14-L06

  72. 3B-REVIEW-072 · $3.45

    Total spent $6.55; subtract from $10.00 to obtain $3.45.

    Related competency: MATH-3B-C15-L03, MATH-3B-C15-L05

  73. 3B-REVIEW-073 · 99 cents

    The dollar amounts have the same whole-dollar part. Subtract $9.00 from $9.99 to get $0.99, which is 99 cents.

    Related competency: MATH-3B-C15-L01, MATH-3B-C15-L04

  74. 3B-REVIEW-074 · $15.90

    2×$6.75=$13.50; add $2.40 to get $15.90.

    Related competency: MATH-3B-C15-L05

Examination answer key

  1. 3B-EXAM-001 · 42 chairs

    Five groups of 7 give 35 chairs; another group adds 7, so 35 + 7 = 42.

    Related competency: MATH-3B-C08-L01

  2. 3B-EXAM-002 · 56 plants

    Four rows have 4 × 8 = 32 plants; three rows have 3 × 8 = 24. Together 32 + 24 = 56.

    Related competency: MATH-3B-C08-L02

  3. 3B-EXAM-003 · No; 7 × 8 = 7 × 5 + 7 × 3 = 56

    The groups must have the same factor 7 in both pieces: 7 × (5+3) = 35+21 = 56. The proposed second term, 8 × 3, changes the quantity.

    Related competency: MATH-3B-C08-L03

  4. 3B-EXAM-004 · 13 stacks

    91 ÷ 7 = 13; 13 × 7 = 91, with no books remaining.

    Related competency: MATH-3B-C08-L04

  5. 3B-EXAM-005 · 72

    2 × 9 = 18; doubling gives 4 × 9 = 36; doubling again gives 8 × 9 = 72.

    Related competency: MATH-3B-C08-L06

  6. 3B-EXAM-006 · 63

    Ten sevens is 70; remove one seven to make nine sevens: 70 − 7 = 63.

    Related competency: MATH-3B-C08-L07

  7. 3B-EXAM-007 · 8 × 6 is larger by 3

    Eight sixes is 48; nine fives is 45. Their difference is 48 − 45 = 3.

    Related competency: MATH-3B-C08-L08

  8. 3B-EXAM-008 · 9 minibuses

    74 ÷ 9 = 8 remainder 2. Eight full minibuses carry 72 children; two remain, requiring a ninth minibus.

    Related competency: MATH-3B-C08-L09

  9. 3B-EXAM-009 · 4/6

    Four of six equal pieces are colored. The unit fraction 1/6 is the amount in one of those six equal pieces.

    Related competency: MATH-3B-C09-L01

  10. 3B-EXAM-010 · 6/8 (equivalent to 3/4)

    Eight equal intervals span 0 to 1. Each tick adds 1/8, so the sixth tick is 6/8. Counting intervals—not just interior tick marks—sets the denominator.

    Related competency: MATH-3B-C09-L02

  11. 3B-EXAM-011 · 9/11, by 5/11

    With the same whole and denominator, compare numerators: 9 > 4. Difference = (9−4)/11 = 5/11.

    Related competency: MATH-3B-C09-L03

  12. 3B-EXAM-012 · 2/7 < 2/5 < 2/3

    All have numerator 2. Splitting the same whole into more equal parts makes each part smaller; sevenths are smallest and thirds largest.

    Related competency: MATH-3B-C09-L04

  13. 3B-EXAM-013 · Each equals the same quantity

    Dividing each of the three equal thirds into two equal parts creates six parts; four sixths covers the same interval as two thirds.

    Related competency: MATH-3B-C10-L01

  14. 3B-EXAM-014 · 10/16 and 15/24

    5/8 = (5×2)/(8×2) = 10/16, and (5×3)/(8×3) = 15/24. Multiplying by 1 in fractional form preserves the value.

    Related competency: MATH-3B-C10-L02

  15. 3B-EXAM-015 · 2/3

    Subtracting equal amounts does not preserve a fraction. Divide both by their common factor 5 instead: 10/15 = 2/3.

    Related competency: MATH-3B-C10-L03

  16. 3B-EXAM-016 · 3/4

    4/6 = 8/12; 3/4 = 9/12. Nine twelfths is greater than eight twelfths.

    Related competency: MATH-3B-C10-L04

  17. 3B-EXAM-017 · No; 4/7 < 3/5

    4/7 = 20/35; 3/5 = 21/35. Fractions are not ordered by denominator size alone.

    Related competency: MATH-3B-C10-L05

  18. 3B-EXAM-018 · 1/3 L

    9/12 − 5/12 = 4/12 = 1/3 L; subtract like-sized twelfths.

    Related competency: MATH-3B-C10-L07

  19. 3B-EXAM-019 · 5/8 m

    1/4 = 2/8; subtract 7/8 − 2/8 = 5/8 m. The fractions refer to the same-sized meter whole.

    Related competency: MATH-3B-C10-L08

  20. 3B-EXAM-020 · 2 m 78 cm

    Two complete groups of 100 cm are 2 meters, leaving 78 cm.

    Related competency: MATH-3B-C11-L01

  21. 3B-EXAM-021 · 2 m 52 cm

    3 m 8 cm = 2 m 108 cm. Then 108−56=52 cm, so 2 m 52 cm remains.

    Related competency: MATH-3B-C11-L02

  22. 3B-EXAM-022 · 5 km 26 m

    5 groups of 1,000 m make 5 km, with 26 m remaining.

    Related competency: MATH-3B-C11-L03

  23. 3B-EXAM-023 · 3 km 440 m

    4 km 90 m = 3 km 1,090 m; 1,090−650=440 m, so 3 km 440 m remains.

    Related competency: MATH-3B-C11-L04

  24. 3B-EXAM-024 · 3 L 75 mL

    Three thousands of milliliters are 3 L, with 75 mL remaining.

    Related competency: MATH-3B-C11-L05

  25. 3B-EXAM-025 · 2 kg 640 g

    Two complete 1,000 g units are 2 kg; 640 g remain.

    Related competency: MATH-3B-C11-L06

  26. 3B-EXAM-026 · 3 m 63 cm

    175 cm + 248 cm = 423 cm; 423−60=363 cm = 3 m 63 cm.

    Related competency: MATH-3B-C11-L07

  27. 3B-EXAM-027 · Radii 4 cm and 7 cm; second circle is larger

    Each radius is half the diameter. The second radius is larger, so its circle is larger.

    Related competency: MATH-3B-C12-L01

  28. 3B-EXAM-028 · Yes, obtuse

    Angle size is the amount of turn between rays. A 120° turn is greater than 90° and less than 180°, regardless of ray lengths.

    Related competency: MATH-3B-C12-L02

  29. 3B-EXAM-029 · Right angle, 90°

    A square corner provides a right-angle reference, which is precisely a quarter turn of 360° or 90°.

    Related competency: MATH-3B-C12-L03

  30. 3B-EXAM-030 · Equilateral; three equal angles

    All three sides are equal, so it is equilateral. In Euclidean geometry its three interior angles are equal (each 60°).

    Related competency: MATH-3B-C12-L04

  31. 3B-EXAM-031 · Those two angles are equal

    In a triangle, equal sides face equal interior angles. This property is independent of the triangle’s orientation.

    Related competency: MATH-3B-C12-L05

  32. 3B-EXAM-032 · Rhombus yes; square no

    A rhombus has four equal sides. A square also requires four right angles, which this quadrilateral lacks.

    Related competency: MATH-3B-C12-L06

  33. 3B-EXAM-033 · Two circles drawn around one center O; radii correctly labeled 2 cm and 4 cm

    Mark O and keep the compass point fixed at O. Draw the first circle with a 2 cm opening, then draw the second with a 4 cm opening. Label radii from O to both boundaries. Both circles must share O.

    Related competency: MATH-3B-C12-L07

  34. 3B-EXAM-034 · No; tiles must cover the region without gaps or overlaps

    An overlapping tile double-counts some area, while an uncovered corner is not measured at all. Arrange equal square tiles to cover the region exactly once, without gaps or overlaps, before counting.

    Related competency: MATH-3B-C13-L01

  35. 3B-EXAM-035 · 24 cm²

    The child counted two-dimensional squares, so the unit must be square centimeters (cm²), not a length unit.

    Related competency: MATH-3B-C13-L02

  36. 3B-EXAM-036 · 8 m

    Rectangle area = length × width. Divide 48 m² by 6 m to get 8 m.

    Related competency: MATH-3B-C13-L03

  37. 3B-EXAM-037 · 38 m²

    First region 5×4=20 m²; second 3×6=18 m². They do not overlap, so sum 20+18=38 m².

    Related competency: MATH-3B-C13-L04

  38. 3B-EXAM-038 · No; perimeter is 22 cm

    4×7=28 cm² is area. Perimeter = 4+7+4+7 = 22 cm around the boundary.

    Related competency: MATH-3B-C13-L06

  39. 3B-EXAM-039 · 9 cm

    Half the perimeter is length + width = 15 cm; subtract width 6 cm to get length 9 cm.

    Related competency: MATH-3B-C13-L07

  40. 3B-EXAM-040 · 16 and 24 square units

    Both perimeters equal 2(2+8)=20 and 2(4+6)=20. Areas differ: 2×8=16 and 4×6=24. Equal perimeter need not give equal area.

    Related competency: MATH-3B-C13-L08

  41. 3B-EXAM-041 · 17 days

    Two weeks equals 2×7=14 days; 14+3=17 days.

    Related competency: MATH-3B-C14-L01

  42. 3B-EXAM-042 · 47 minutes

    2:35→3:00 takes 25 min; 3:00→3:22 takes 22 min; total 47 min.

    Related competency: MATH-3B-C14-L02

  43. 3B-EXAM-043 · 10:15 a.m.

    Count backward 10 minutes to 11:00 a.m. and another 45 minutes to 10:15 a.m.

    Related competency: MATH-3B-C14-L04

  44. 3B-EXAM-044 · 45 minutes

    11:35 p.m.→midnight takes 25 min; midnight→12:20 a.m. takes 20 min; total 45 min.

    Related competency: MATH-3B-C14-L05

  45. 3B-EXAM-045 · 3:15 p.m.

    Total duration = 40+15+35 = 90 min (1 h 30 min); 1:45 p.m. + 90 min = 3:15 p.m.

    Related competency: MATH-3B-C14-L06

  46. 3B-EXAM-046 · $6.35

    Six groups of 100 cents make $6, and 35 cents remain: $6.35.

    Related competency: MATH-3B-C15-L01

  47. 3B-EXAM-047 · $5.24

    $10.00−$4.76=$5.24; check $4.76+$5.24=$10.00.

    Related competency: MATH-3B-C15-L02

  48. 3B-EXAM-048 · $15.63

    Align dollars and cents: 8.95+6.68=15.63. The cents total $1.63, so regroup one dollar.

    Related competency: MATH-3B-C15-L03

  49. 3B-EXAM-049 · $12.27

    In cents: 1,505−278 = 1,227 cents = $12.27. Exchange one dollar to handle the cents.

    Related competency: MATH-3B-C15-L04

  50. 3B-EXAM-050 · $12.50

    Cost = $18.75+$18.75=$37.50; $50.00−$37.50=$12.50 change.

    Related competency: MATH-3B-C15-L05

  51. 3B-EXAM-051 · 6 complete rows and 6 extra

    6×9=54 students; 54 ÷ 8 = 6 remainder 6. The remainder cannot fill another complete row.

    Related competency: MATH-3B-C08-L01, MATH-3B-C08-L09

  52. 3B-EXAM-052 · 5/6

    With five pieces, sixth-pieces are larger than eighth-pieces; 5/6 > 5/8.

    Related competency: MATH-3B-C09-L04

  53. 3B-EXAM-053 · 7/8 L

    1/2 = 4/8. Add 4/8+3/8=7/8 L. The denominators represent consistent equal units.

    Related competency: MATH-3B-C10-L02, MATH-3B-C10-L08

  54. 3B-EXAM-054 · 1 kg 375 g

    4,000 g−1,650 g−975 g=1,375 g=1 kg 375 g.

    Related competency: MATH-3B-C11-L06, MATH-3B-C11-L07

  55. 3B-EXAM-055 · They are the same size

    The circle with 10 cm diameter has radius 5 cm, so both have the same radius. For circles, equal radius means equal size.

    Related competency: MATH-3B-C12-L01

  56. 3B-EXAM-056 · Same grass area; first needs more fencing

    Areas 36 m² for both. Perimeters 2(4+9)=26 m and 2(6+6)=24 m; first uses 2 more meters of fence.

    Related competency: MATH-3B-C13-L03, MATH-3B-C13-L07, MATH-3B-C13-L08

  57. 3B-EXAM-057 · 32 minutes

    Total elapsed 12 minutes to midnight + 27 minutes after midnight =39 minutes; subtract 7 minutes stationary =32 minutes moving.

    Related competency: MATH-3B-C14-L05, MATH-3B-C14-L06

  58. 3B-EXAM-058 · $11.95

    Start with $25.00; subtract $8.85 and $7.70 to get $8.45; add $3.50 to get $11.95.

    Related competency: MATH-3B-C15-L03, MATH-3B-C15-L04, MATH-3B-C15-L05