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 Work it out in your head: 302 − 97
Show worked solution
302 − 100 = 202, but you took 3 too many, so give them back: 205.
2 Work it out in your head: 85 − 28
Show worked solution
85 − 25 = 60, then 60 − 3 = 57.
3 Take 199 away from 462.
Show worked solution
462 − 200 = 262, then give back the 1 you over-subtracted: 263.
Level 2 · Core
4 Work it out in your head: 1000 − 640
Show worked solution
Count up: 640 + 60 = 700, then 700 + 300 = 1000. That is 60 + 300 = 360.
5 What is the difference between 803 and 358?
Show worked solution
803 − 358: take 300 to get 503, then 58 more gives 445.
6 Use compensation: 574 − 298
Show worked solution
574 − 300 = 274, and you took 2 too many, so 276.
Level 3 · Challenge
7 I subtracted 176 from a number and got 248. What was the number?
Show worked solution
Add back what was taken: 248 + 176 = 424. (Check: 424 − 176 = 248.)
8 The difference between two numbers is 150. The larger one is 400. What is the smaller one?
Show worked solution
400 − 150 = 250.
9 Start at 1000. Subtract 250, then subtract half of what is left. What number do you finish with?
Show worked solution
1000 − 250 = 750. Half of 750 is 375, and 750 − 375 = 375.
⭐ Bonus Challenge · only if the rest felt easy
10 Use a smart strategy: 302 − 98
Show worked solution
Take 100: 302 − 100 = 202. You took away 2 too many, so add them back: 202 + 2 = 204.