3A · Chapter 4 · Practice
Chapter review
Attempt independently, then review the full reasoning in the answer key.
Attempt independently, then review the full reasoning in the answer key. No name, account, or answer is transmitted to any server.
Assessment · 31 questions
Problems
The complete solutions are available here after each question and on the printable answer-key page.
- A1
Each of 3 shelves holds 25 equally sized boxes. How many boxes altogether?
Show answer and reasoning
Answer: 75
The total is 3 equal groups of 25: 3 × 25 = 75.
- A2
A store has 9 packs of 18 markers, then sells 24 markers. How many remain?
Show answer and reasoning
Answer: 138
First find total 9×18=162, then subtract 24 to get 138.
- A3
Sam has 32 beads. Nora has 2 times as many. How many beads does Nora have?
Show answer and reasoning
Answer: 64
Draw one unit 32 for Sam and 2 matching units for Nora: 32 × 2 = 64.
- A4
Each of 12 shelves holds 18 equally sized boxes. How many boxes altogether?
Show answer and reasoning
Answer: 216
The total is 12 equal groups of 18: 12 × 18 = 216.
- A5
Calculate 14 × 7 by splitting 14 into tens and ones.
Show answer and reasoning
Answer: 98
(10+4)×7=(10×7)+(4×7)=98.
- A6
Is 158 + 57 odd or even? Explain using pairs.
Show answer and reasoning
Answer: odd
158 is even, 57 is odd; their sum 215 is odd because 215 leaves 1 unpaired item.
- A7
30 counters are shared equally among 6 children. How many does each receive?
Show answer and reasoning
Answer: 5
6 equal groups contain 30 counters: 30÷6=5; verify 5×6=30.
- A8
There are 47 children; each team can hold 6. How many complete teams form, and how many children remain?
Show answer and reasoning
Answer: 7 teams, 5 left
6×7=42, with 47−42=5 children left.
- A9
65 oranges are packed into bags holding 8 each. How many FULL bags and how many oranges left?
Show answer and reasoning
Answer: 8 bags, 1 left
65=8×8+1; since 1<8, 8 bags are full and 1 oranges remain.
- A10
Calculate 21 × 8 by splitting 21 into tens and ones.
Show answer and reasoning
Answer: 168
(20+1)×8=(20×8)+(1×8)=168.
- A11
There are 5 equal rows with 10 counters each. How many counters?
Show answer and reasoning
Answer: 50
There are 5 groups of 10; multiply 5×10=50. Turning the array does not change the total.
- A12
Explain why 8×(5+2) is the same as 8×5+8×2.
Show answer and reasoning
Answer: 56
Eight copies of the two-part sum contain 40 of the first part and 16 of the second.
- A13
Give an array with 30 counters that has more rows than columns, and a rotated version.
Show answer and reasoning
Answer: 6×5 and 5×6
Both rectangles have 30 cells; rotating swaps rows and columns without changing count.
- A14
Sam has 6 beads. Nora has 3 times as many. How many beads does Nora have?
Show answer and reasoning
Answer: 18
Draw one unit 6 for Sam and 3 matching units for Nora: 6 × 3 = 18.
- A15
A store has 10 packs of 7 markers, then sells 29 markers. How many remain?
Show answer and reasoning
Answer: 41
First find total 10×7=70, then subtract 29 to get 41.
- A16
Each of 5 shelves holds 9 equally sized boxes. How many boxes altogether?
Show answer and reasoning
Answer: 45
The total is 5 equal groups of 9: 5 × 9 = 45.
- A17
Is 124 + 35 odd or even? Explain using pairs.
Show answer and reasoning
Answer: odd
124 is even, 35 is odd; their sum 159 is odd because 159 leaves 1 unpaired item.
- A18
There are five boxes of 9 pencils each. Four are broken. How many usable pencils?
Show answer and reasoning
Answer: 41
5×9=45; 45−4=41.
- A19
Calculate 69 × 0, and explain why.
Show answer and reasoning
Answer: 0
The meaning of equal groups gives 0. One group preserves a quantity; zero groups give zero; zero split among nonzero groups is zero.
- A20
Calculate 62 × 1, and explain why.
Show answer and reasoning
Answer: 62
The meaning of equal groups gives 62. One group preserves a quantity; zero groups give zero; zero split among nonzero groups is zero.
- A21
48 counters are shared equally among 4 children. How many does each receive?
Show answer and reasoning
Answer: 12
4 equal groups contain 48 counters: 48÷4=12; verify 12×4=48.
- A22
Calculate 82 × 6 by splitting 82 into tens and ones.
Show answer and reasoning
Answer: 492
(80+2)×6=(80×6)+(2×6)=492.
- A23
There are 6 equal rows with 8 counters each. How many counters?
Show answer and reasoning
Answer: 48
There are 6 groups of 8; multiply 6×8=48. Turning the array does not change the total.
- A24
Calculate 0 ÷ 76, and explain why.
Show answer and reasoning
Answer: 0
The meaning of equal groups gives 0. One group preserves a quantity; zero groups give zero; zero split among nonzero groups is zero.
- A25
45 oranges are packed into bags holding 2 each. How many FULL bags and how many oranges left?
Show answer and reasoning
Answer: 22 bags, 1 left
45=2×22+1; since 1<2, 22 bags are full and 1 oranges remain.
- A26
143 oranges are packed into bags holding 9 each. How many FULL bags and how many oranges left?
Show answer and reasoning
Answer: 15 bags, 8 left
143=9×15+8; since 8<9, 15 bags are full and 8 oranges remain.
- A27
There are 4 equal rows with 3 counters each. How many counters?
Show answer and reasoning
Answer: 12
There are 4 groups of 3; multiply 4×3=12. Turning the array does not change the total.
- A28
Sam has 9 beads. Nora has 4 times as many. How many beads does Nora have?
Show answer and reasoning
Answer: 36
Draw one unit 9 for Sam and 4 matching units for Nora: 9 × 4 = 36.
- A29
Is 141 + 46 odd or even? Explain using pairs.
Show answer and reasoning
Answer: odd
141 is odd, 46 is even; their sum 187 is odd because 187 leaves 1 unpaired item.
- A30
A store has 3 packs of 10 markers, then sells 6 markers. How many remain?
Show answer and reasoning
Answer: 24
First find total 3×10=30, then subtract 6 to get 24.
- A31
75 counters are shared equally among 5 children. How many does each receive?
Show answer and reasoning
Answer: 15
5 equal groups contain 75 counters: 75÷5=15; verify 15×5=75.