Vertical Addition and Subtraction Within 20
Numbers stacked, a line underneath and room for the answer: vertical addition and subtraction within 20, twenty problems for first graders aged 6-7.
2 A4 pages · for home and classroom use
Labugen
Addition and subtraction up to 20
set no. 106
- 17+3
- 4+11
- 13+2
- 4+1
- 1+5
- 8+10
- 2-1
- 17-16
- 9+2
- 7+4
- 2+7
- 9-4
- 7-5
- 16-10
- 6-1
- 12+5
- 7-2
- 10-3
- 6+12
- 3+17
How to use this worksheet
- Point at the sign before solving: twelve problems add and eight subtract, mixed together.
- Work across each row of five; the answer goes in the space under the line.
- In problems such as 17 + 3 or 10 − 3, start with the ones and say what happens when they make 10 or are not enough.
- The practice problems are not numbered, so match them to the answer key by counting across: the first row is 1-5, the second 6-10.
What this worksheet teaches
Writing problems vertically is the first step toward column arithmetic. The numbers are printed right-aligned, so a one-digit number such as the 3 in 17 + 3 sits under the 7, never under the 1. Children practice facts within 20 in the layout they will later use for bigger numbers. Five problems need regrouping (17 + 3, 3 + 17, 9 + 2, 7 + 4 and 10 − 3); the rest do not.
Why the ones line up
In column work, each column holds one place: ones on the right, tens to their left. Lining up the ones keeps like with like: 8 + 10 is 8 ones plus 1 ten, giving 18. A common early mistake is pushing a small number to the left; the printed layout always shows the correct position.