Roots of Reason
Roots of Reason
rootsofreason.org
Fluency Drill
Two 2-Digit Numbers, No Paper · Grade 4

Mental Addition Drill

Name Date Time Score / 20
Find the sums in your head - tens first, then ones. No column work.
1. 28 + 10 = 2. 22 + 44 = 3. 51 + 19 = 4. 70 + 18 = 5. 60 + 12 = 6. 29 + 66 = 7. 21 + 66 = 8. 30 + 18 = 9. 45 + 34 = 10. 89 + 11 = 11. 18 + 72 = 12. 28 + 67 = 13. 31 + 55 = 14. 13 + 45 = 15. 32 + 31 = 16. 13 + 49 = 17. 68 + 24 = 18. 26 + 28 = 19. 43 + 10 = 20. 22 + 55 =
Roots of Reason CA CCSS 4.NBT.B.4 · Fluency Drill rootsofreason.org · Page 1 of 2
Roots of Reason
Roots of Reason
rootsofreason.org
Answer Key
Two 2-Digit Numbers, No Paper · Grade 4

Mental Addition Drill

1. 28 + 10 = 38 2. 22 + 44 = 66 3. 51 + 19 = 70 4. 70 + 18 = 88 5. 60 + 12 = 72 6. 29 + 66 = 95 7. 21 + 66 = 87 8. 30 + 18 = 48 9. 45 + 34 = 79 10. 89 + 11 = 100 11. 18 + 72 = 90 12. 28 + 67 = 95 13. 31 + 55 = 86 14. 13 + 45 = 58 15. 32 + 31 = 63 16. 13 + 49 = 62 17. 68 + 24 = 92 18. 26 + 28 = 54 19. 43 + 10 = 53 20. 22 + 55 = 77