Work through the levels in order. Type your answer and press Check — open the worked solution if you get stuck. Answers like -6, 3/4 or 0.25 are typed exactly as shown. A ⭐ Bonus Challenge at the end is extra credit — skip it if the rest was hard work.
Level 1 · Warm-up
1 Column subtract: 624 − 287
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Trade a ten: 14 − 7 = 7. Tens: 1 − 8 needs a trade from the hundreds: 11 − 8 = 3. Hundreds: 5 − 2 = 3. Answer 337.
2 Column subtract: 700 − 246
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Trade across the zeros: 700 becomes 6 hundreds, 9 tens, 10 ones. 10 − 6 = 4, 9 − 4 = 5, 6 − 2 = 4. Answer 454.
3 Column subtract: 1503 − 728
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Ones: 13 − 8 = 5 (traded). Tens: 9 − 2 = 7 (traded from the hundreds). Hundreds: 4 − 7 needs a trade from the thousands: 14 − 7 = 7. Answer 775.
Level 2 · Core
4 Column subtract: 4002 − 1897
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Easiest by compensation: 4002 − 1900 = 2102, and you took 3 too many, so 2105.
5 A number take away 385 leaves 617. What was the number?
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617 + 385 = 1002. (Check: 1002 − 385 = 617.)
6 Column subtract: 8050 − 3675
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Ones: 10 − 5 = 5 (traded). Tens: 4 − 7 needs a trade: 14 − 7 = 7. Hundreds: 9 − 6 = 3. Thousands: 7 − 3 = 4. Answer 4375.
Level 3 · Challenge
7 In this subtraction, 6▢2 − 348 = 294. What digit belongs in the box?
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294 + 348 = 642, so the first number is 642 and the box holds 4.
8 I subtracted a number from 900 and got 358. If I subtract the same number from 1000, what do I get?
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Starting 100 higher and taking away the same amount leaves 100 more: 358 + 100 = 458. (The hidden number is 542.)
9 Two numbers have a difference of 246. The smaller one is 377. What is the larger one?
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377 + 246 = 623. (Check: 623 − 377 = 246.)
⭐ Bonus Challenge · only if the rest felt easy
10 A number minus 268 equals 175. Find that number, then subtract 96 from it. What is your final answer?
Show worked solution
The number is 175 + 268 = 443. Then 443 − 96 = 347.