You said: 110
Correct! 55 + 55 equals 110.

The correct answer is 55 + 55 equals 110.

You said: 111
That's one too many. The correct answer is 110.

You said: 105
Not quite - the correct answer is 110.

You said: 115
No - you've added an extra 5. The correct answer is 110.

You said: 35
That's right! 55 - 20 is 35.

The correct answer for 55 - 20 is 35.

You said: 75
No, you've added the two numbers together by mistake instead of taking away. The correct answer is 35.

You said: 30
Not quite. The correct answer for 55 - 20 is 35. You could try counting on from 20.

You said: 20
No, that's too low. The correct answer for 55 - 20 is 35. You could try counting on from 20.

You said: 500
That's the one. 300 + 200 = 500.

The correct answer is 500. Try rounding up each number to the nearest 100 and then adding them together. 300 + 200 = 500.

You said: 300
You've only looked at the first number. Don't forget that 99 is nearly 100. The correct way to work it out is 300 + 200 = 500.

You said: 100
Not quite - the correct answer is 500. Try rounding up each number to the nearest 100 and then adding them together. 300 + 200 = 500.

You said: 400
Not quite - the correct answer is 500. It's best to round up to the nearest 100. 300 + 200 = 500.

You said: The total will be 2 less than my estimate
You're right - you rounded up each of the two numbers by 1, so the correct answer is 500 minus 2 = 498.

To reach the estimate of 500 you needed to round up both of the amounts by 1, so you needed to take 2 off the estimate. The correct answer is 500 minus 2 = 498.

You said: The total will be 2 more than my estimate
No, not quite. You needed to round up each of the four numbers by 1, so you needed to take 2 off the estimate. The correct answer is 500 minus 2 = 498.

You said: I'm not sure
If you're not sure, it's always sensible to say so. To reach the estimate of 500 you needed to round up both of the amounts by 1, so you needed to take 2 off the estimate. The correct answer is 500 minus 2 = 498.

You said: The cost will be 4 less than my estimate
No, not quite. You needed to round up each of the four numbers by 1, so you needed to take 2 off the estimate. The correct answer is 500 minus 2 = 498.

You said: 220
That's right. 399 - 179 = 220

The correct answer is 399 - 179 = 220.

You said: 200
No - that's a fair estimate but you want an exact figure. You could try counting on from 179. The correct answer is 399 - 179 = 220.

You said: 230
No - that's a fair estimate but you want an exact figure. You could try counting on from 179. The correct answer is 399 - 179 = 220.

You said: 578
Oops - you've added instead of subtracting. The correct answer is 399 - 179 = 220. You could try counting on from 179.

You said: 361
Well done! The correct answer is 179 + 182 = 361.

The correct answer is 179 + 182 = 361.

You said: 261
Bad luck, but you have missed out 100. Why not try doubling the numbers? The correct answer is 179 + 182 = 361.

You said: 282
No - you've forgotten to add in 79. The correct answer is 179 + 182 = 361. Have you tried doubling?

You said: 369
Nearly right - did you try doubling, rounding up and forget to subtract the 2? The correct answer is 179 + 182 = 361.

You said: 96
You're right! 78 + 18 is 96.

The correct answer is 78 + 18 is 96.

You said: 98
No, that's 2 too many. The correct answer is 78 + 18 is 96. Have you tried rounding up?

You said: 60
Oops - you've subtracted instead of adding. The correct answer is 78 + 18 is 96. Have you tried rounding up?

You said: 97
Nearly - I think you just made a slip and added 19. The correct answer is 78 + 18 is 96. Have you tried rounding up?

You said: 114
That's right - the correct answer is 65 + 49 = 114.

The correct answer is 65 + 49 = 114

You said: 115
Nearly right - the correct answer is 65 + 49 = 114. You could have added 50 to 65 then taken away 1.

You said: 116
Nearly right - the correct answer is 65 + 49 = 114. You could have added 50 to 65 then taken away 1.

You said: 214
Nearly right - the correct answer is 65 + 49 = 114. You could have added 50 to 65 then taken away 1.

You said: 250
Well done! The correct answer is 1 549 - 1 299 = 250.

The correct answer is 1 549 - 1 299 = 250.

You said: 249
Close, but not quite right! The correct answer is 1 549 - 1 299 = 250. You could say 1 300 to 1 549 is 249, then add in the extra 1.

You said: 349
Oops - not sure what you did there. The correct answer is 1 549 - 1 299 = 250. You could say 1 300 to 1 549 is 249, then add in the extra 1.

You said: 350
No - the correct answer is 1 549 - 1 299 = 250. You could add 1 to both numbers to make the sum 1 550 - 1 300. Then counting on from 1 300 to 1 550 is 250.

You said: 60
You're right. the sum is 129 - 69 = 60

Would you like to have another go or try a different level?

The sum is 129 - 69 = 60

Would you like to have another go or try a different level?

You said: 59
Not quite right - the sum is 129 - 69 = 60. Next time you could try counting on from 69.

Would you like to have another go or try a different level?

You said: 50
You've lost 10 somewhere! The sum is 129 - 69 = 60. You could try counting on from 69.

Would you like to have another go or try a different level?

You said: 90
You seem to have added in 30. The sum is 129 - 69 = 60. You could try counting on from 69.

Would you like to have another go or try a different level?