Grade 2 Mathematics Additions – Adding Single Digits Vertically Notes
Mathematics — Additions
Subtopic: Adding Single Digits Vertically
Target: Kenyan learners aged 7 (Standard 2). In this lesson we learn how to add two single digits when they are written one above the other (vertically).
- Write the numbers one under the other so the digits line up (units under units).
- Start from the top or bottom? We look at the units column (the single digits) and add them.
- If the sum is less than 10, write the total under the line (no carry).
- If the sum is 10 or more, write the ones digit under the line and put the tens (the carry) above the next column (we write 1 above the tens column).
4
+ 3
7
We add 4 and 3. 4 + 3 = 7. No carry.
1
9
+ 6
1 5
9 + 6 = 15. We write 5 under the line and carry 1 to the tens (shown above). So the answer is 15.
2
+ 5
7
7
+ 8
1 5
3
+ 4
7
5
+ 9
1 4
- 6 + 2 =
- 8 + 1 =
- 4 + 7 =
- 9 + 3 =
- 1 + 8 =
- 5 + 5 =
- 7 + 2 =
- 9 + 9 =
Tip: Always line up digits and add the units. If the sum is 10 or more, put the extra 1 (carry) above the next column.
- 6 + 2 = 8
- 8 + 1 = 9
- 4 + 7 = 11 (write 1 and carry 1)
- 9 + 3 = 12 (write 2 and carry 1)
- 1 + 8 = 9
- 5 + 5 = 10 (write 0 and carry 1)
- 7 + 2 = 9
- 9 + 9 = 18 (write 8 and carry 1)