Mental Math Skills Quiz: Adding three-digit numbers without a calculator

Math  |  addition
Mental Math Skills Quiz: Adding three-digit numbers without a calculator
My score

Free online printable quiz with multiple-choice questions (MCQ) without registration.

By solving examples with simple arithmetic operations, such as addition and subtraction, we actively and effectively train our brains. This helps it stay in shape, which means we keep a clear mind for years to come. 

The mental math skills quiz "Adding three-digit numbers without a calculator" consists of 20 questions of varying difficulty. Try them all in 7-10 minutes. If it takes you less than 5 minutes, you're in great shape! 

Test yourself

Found a mistake? Select it and press Ctrl+Enter

For each question choose one of the multiple answers then click done to check your results.

1. 901 + 365 = ...

2. 221 + 342 = ...

3. 555 + 555 + 555 =

4. 666 + 999 = ...

5. 384 + 121 + 501 = ...

6. 438 + 321 + 101 = ...

7. 106 + 111 + 121 = ...

8. 135 + 185 = ...

9. 222 + 444 + 666 = ...

10. 323 + 181 = ...

11. 577 + 342 = ...

12. 321 + 432 + 543 = ...

13. 834 + 563 = ...

14. 181 + 389 = ...

15. 561 + 322 = ...

16. 381 + 183 = ...

17. 101 + 100 + 111 = ...

18. 412 + 320 + 201 = ...

19. 123 + 456 + 789 = ...

20. 432 + 578 + 235 = ...

**********