3A · Chapter 2 · Practice
Practice B
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 · 15 questions
Problems
The complete solutions are available here after each question and on the printable answer-key page.
- A1
Calculate 2,003 − 98 by using a nearby hundred.
Show answer and reasoning
Answer: 1905
Rewrite 98 as the nearby multiple of 100 with a small correction. Apply the correction to 2,003 and check the exact answer 1,905.
- A2
Calculate 2,129 + 199 by using a nearby hundred.
Show answer and reasoning
Answer: 2328
Rewrite 199 as the nearby multiple of 100 with a small correction. Apply the correction to 2,129 and check the exact answer 2,328.
- A3
Calculate 2,255 − 301 by using a nearby hundred.
Show answer and reasoning
Answer: 1954
Rewrite 301 as the nearby multiple of 100 with a small correction. Apply the correction to 2,255 and check the exact answer 1,954.
- A4
Two collections contain 200 items altogether. One has 10 more than the other. How many are in EACH collection?
Show answer and reasoning
Answer: 95 and 105
Remove the extra 10; 200 − 10 = 190. Two equal parts are 95 each. Larger part is 95 + 10 = 105.
- A5
Two collections contain 240 items altogether. One has 24 more than the other. How many are in EACH collection?
Show answer and reasoning
Answer: 108 and 132
Remove the extra 24; 240 − 24 = 216. Two equal parts are 108 each. Larger part is 108 + 24 = 132.
- A6
Two collections contain 90 items altogether. One has 38 more than the other. How many are in EACH collection?
Show answer and reasoning
Answer: 26 and 64
Remove the extra 38; 90 − 38 = 52. Two equal parts are 26 each. Larger part is 26 + 38 = 64.
- A7
A school library has 320 books. 110 are on the front shelf. How many are elsewhere?
Show answer and reasoning
Answer: 210
The 320 books are the whole, 110 is a part. Subtract: 320 − 110 = 210.
- A8
A school library has 361 books. 127 are on the front shelf. How many are elsewhere?
Show answer and reasoning
Answer: 234
The 361 books are the whole, 127 is a part. Subtract: 361 − 127 = 234.
- A9
A school library has 402 books. 144 are on the front shelf. How many are elsewhere?
Show answer and reasoning
Answer: 258
The 402 books are the whole, 144 is a part. Subtract: 402 − 144 = 258.
- A10
Leo collected 245 stamps. Mina collected 30 more than Leo. How many does Mina have?
Show answer and reasoning
Answer: 275
Draw Leo’s bar of 245; add the extra segment 30. Mina’s total is 245+30=275.
- A11
Leo collected 276 stamps. Mina collected 39 more than Leo. How many does Mina have?
Show answer and reasoning
Answer: 315
Draw Leo’s bar of 276; add the extra segment 39. Mina’s total is 276+39=315.
- A12
Leo collected 307 stamps. Mina collected 48 more than Leo. How many does Mina have?
Show answer and reasoning
Answer: 355
Draw Leo’s bar of 307; add the extra segment 48. Mina’s total is 307+48=355.
- A13
A shop begins with 310 pencils, receives 80, then sells 10. How many pencils remain?
Show answer and reasoning
Answer: 380
First 310+80=390; then take away 10. Result: 380.
- A14
A shop begins with 367 pencils, receives 93, then sells 27. How many pencils remain?
Show answer and reasoning
Answer: 433
First 367+93=460; then take away 27. Result: 433.
- A15
A shop begins with 424 pencils, receives 106, then sells 44. How many pencils remain?
Show answer and reasoning
Answer: 486
First 424+106=530; then take away 44. Result: 486.