Two-digit addition without carrying worksheet

Part A: Working out and filling in

1. 1. 18

   Adding a one-digit number only changes the ones. Work out 1 + 7; leave the tens alone.

   Adding a one-digit number changes only the ones: 1 + 7 = 8, the tens stay 1, so 18.

2. 2. 70

   20 is 2 tens and 50 is 5 tens. How many tens is that in all?

   2 tens and 5 tens make 7 tens, which is 70.

3. 3. 90

   10 is a whole number of tens, so only the tens change. Work out 8 + 1; leave the ones alone.

   Adding a whole ten changes only the tens: 8 + 1 = 9, the ones stay 0, so 90.

4. 4. 69

   Adding a one-digit number only changes the ones. Work out 0 + 9; leave the tens alone.

   Adding a one-digit number changes only the ones: 0 + 9 = 9, the tens stay 6, so 69.

5. 5. 90

   20 is 2 tens and 70 is 7 tens. How many tens is that in all?

   2 tens and 7 tens make 9 tens, which is 90.

6. 6. 94

   Tens with tens, ones with ones. Start with the tens digits: 5 and 4.

   Tens with tens: 5 + 4; ones with ones: 0 + 4. The answer is 94.

7. 7. 9, 5, 95

   Split 84 and 11 into tens and ones, then add tens to tens and ones to ones.

   8 + 1 = 9 tens, 4 + 1 = 5 ones, together 95.

8. 8. 9, 8, 98

   Split 15 and 83 into tens and ones, then add tens to tens and ones to ones.

   1 + 8 = 9 tens, 5 + 3 = 8 ones, together 98.

9. 9. 92

   Tens with tens, ones with ones. Start with the tens digits: 8 and 1.

   Tens with tens: 8 + 1; ones with ones: 0 + 2. The answer is 92.

10. 10. 36

    Compare 23 with 59: how many more tens are there, and how many more ones?

    Tens: 2 and 3 make 5; ones: 3 and 6 make 9. So □ is 36; check: 23 + 36 = 59.

11. 11. 63

    Compare 11 with 74: how many more tens are there, and how many more ones?

    Tens: 1 and 6 make 7; ones: 1 and 3 make 4. So □ is 63; check: 11 + 63 = 74.

Part B: Choose, or true or false

1. 12. True

   Work it out yourself: tens with tens, ones with ones, then compare with 66.

   Tens with tens, ones with ones: 54 + 12 = 66.

Part C: Word problems

Marking: 2 for the working, 1 for the answer, 1 for the sentence.

1. 13. 78 skips

   The second go is 38 more than the first, so add: tens with tens, ones with ones.

   38 more than 40, so add: 40 + 38 = 78.

2. 14. 77 passengers

   More people get on, so add. Adding a one-digit number only changes the ones.

   Getting on means more, so add: 74 + 3 = 77; only the ones change.

3. 15. 40 eggs

   With 10 to a box, 30 eggs fill 3 boxes and 10 fill 1 more. How many boxes is that?

   3 boxes and 1 boxes, that is 3 tens and 1 tens: 30 + 10 = 40.

4. 16. 96 stickers

   Being given more means adding. Tens with tens, ones with ones.

   Being given more puts them together, so add: 53 + 43 = 96.

5. 17. 95 passengers

   More people get on, so add. Adding a one-digit number only changes the ones.

   Getting on means more, so add: 93 + 2 = 95; only the ones change.

6. 18. 76 stickers

   Being given more means adding. Tens with tens, ones with ones.

   Being given more puts them together, so add: 65 + 11 = 76.