3A · Chapter 2 · Practice
Chapter practice examination
This original untimed public practice examination is not a secure school or placement test.
This original untimed public practice examination is not a secure school or placement test. No name, account, or answer is transmitted to any server.
Assessment · 22 questions
Problems
The complete solutions are available here after each question and on the printable answer-key page.
- A1
Which is greater: 500−203 or 500−197? By how much?
Show answer and reasoning
Answer: 500−197 by 6
A smaller subtrahend leaves a larger difference. Since 203−197=6, the second expression is six larger.
- A2
Add 1,963 + 435. Show a place-value breakdown.
Show answer and reasoning
Answer: 2398
1,963 is 1,900 + 63; add the two parts to 435. The sum is 2,398.
- A3
A class starts with 214 pencils, adds 86, then gives away 125. Find the amount left.
Show answer and reasoning
Answer: 175
214+86=300; 300−125=175.
- A4
Why is 607−299 the same as 608−300?
Show answer and reasoning
Answer: Equal adjustment
Adding one to both terms leaves their difference 308 unchanged.
- A5
A school library has 520 books. 100 are on the front shelf. How many are elsewhere?
Show answer and reasoning
Answer: 420
The 520 books are the whole, 100 is a part. Subtract: 520 − 100 = 420.
- A6
Find 99 + 383 using compensation.
Show answer and reasoning
Answer: 482
Increase 99 by 1 to get a multiple of 100; then subtract that same adjustment from the total. Result: 482.
- A7
Two collections contain 70 items altogether. One has 10 more than the other. How many are in EACH collection?
Show answer and reasoning
Answer: 30 and 40
Remove the extra 10; 70 − 10 = 60. Two equal parts are 30 each. Larger part is 30 + 10 = 40.
- A8
Invent an addition problem with answer 1,000 using 398 as one addend. State the other.
Show answer and reasoning
Answer: 602
1,000−398=602; 398+602=1,000.
- A9
Nina has 54 tokens and loses 19, then receives 31. Explain why the result is greater than 54.
Show answer and reasoning
Answer: 66
The gain of 31 exceeds the loss of 19 by 12, so final amount is 66.
- A10
Jules has 48 more cards than Ari. Jules has 132 cards. How many does Ari have?
Show answer and reasoning
Answer: 84
Ari’s bar is 48 shorter: 132−48=84.
- A11
A student changes 498+147 to 500+147 but reports 647. Explain the needed correction.
Show answer and reasoning
Answer: 645
Replacing 498 by 500 adds two, so subtract two: 647−2=645.
- A12
Two boxes hold 94 crayons together. One holds 16 more than the other. Find both.
Show answer and reasoning
Answer: 39 and 55
94−16=78; half is 39; other box 39+16=55.
- A13
Use equal adjustment to find 389 − 99.
Show answer and reasoning
Answer: 290
Add 1 to BOTH numbers: 390 − 100 = 290. Their difference is unchanged.
- A14
Why can a sum be solved by adding tens before hundreds, without changing the answer?
Show answer and reasoning
Answer: The parts are unchanged
Regrouping/reordering the same place-value contributions does not alter the total.
- A15
Find 2,554 − 331 by breaking apart the amount subtracted.
Show answer and reasoning
Answer: 2223
Decompose 331 into tens and ones, subtract each part from 2,554, and check the difference 2,223.
- A16
Leo collected 235 stamps. Mina collected 20 more than Leo. How many does Mina have?
Show answer and reasoning
Answer: 255
Draw Leo’s bar of 235; add the extra segment 20. Mina’s total is 235+20=255.
- A17
A gardener bought 195 seedlings on Monday and 208 on Tuesday. Without column arithmetic, give an exact total.
Show answer and reasoning
Answer: 403
200−5 + 200+8 = 400+3=403.
- A18
Two jars hold 120 marbles together. The larger jar has 80. How many more are in the larger jar?
Show answer and reasoning
Answer: 40
Smaller jar is 120−80=40; difference 80−40=40.
- A19
A shop begins with 250 pencils, receives 80, then sells 10. How many pencils remain?
Show answer and reasoning
Answer: 320
First 250+80=330; then take away 10. Result: 320.
- A20
Calculate 1,113 − 98 by using a nearby hundred.
Show answer and reasoning
Answer: 1015
Rewrite 98 as the nearby multiple of 100 with a small correction. Apply the correction to 1,113 and check the exact answer 1,015.
- A21
What must be added to 58 to make 100?
Show answer and reasoning
Answer: 42
The missing part is 100 − 58 = 42; check 58 + 42 = 100.
- A22
At a school 256 students arrive; 79 leave, then 46 arrive. How many are present?
Show answer and reasoning
Answer: 223
256−79=177; 177+46=223.