V.1 Write addition and subtraction sentences for word problems - up to 20
What is an addition and subtraction sentence?
An addition sentence or subtraction sentence is a math sentence that uses numbers and symbols to show what is happening in a word problem.
- Addition: 5 + 3 = 8
- Subtraction: 10 − 4 = 6
Math sentences help explain your thinking and show your answer clearly.
Understanding word problems
A word problem is a math problem written using words. It tells a short story about numbers being added together or taken away.
- Sam has 6 apples. He gets 2 more apples. How many apples does he have now?
Read the word problem carefully and look for clues that tell you what to do.
When to use addition
Use addition when numbers are being put together or when the total is getting bigger.
- Words like add, in all, together, and more often mean add.
- 4 birds are on a tree. 5 more birds join them.
Math sentence: 4 + 5 = 9
Addition answers are usually larger than the numbers you start with.
When to use subtraction
Use subtraction when something is taken away or when you need to find how many are left.
- Words like take away, left, less, and gave away often mean subtract.
- 8 cookies were on a plate. 3 were eaten.
Math sentence: 8 − 3 = 5
Subtraction answers are usually smaller than the number you start with.
Writing a math sentence for a word problem
To write a math sentence, choose the correct operation and use numbers from the word problem.
- There are 12 crayons. 7 are in the box. How many are not in the box?
- Math sentence: 12 − 7 = 5
Check your answer by rereading the problem to see if it makes sense.
Common Core alignment: CCSS.MATH.CONTENT.1.OA.A.1 – Use addition and subtraction within 20 to solve word problems.
Notes for teachers
This free lesson is aligned with CCSS.MATH.CONTENT.1.OA.A.1. Use it for whole-class instruction, small groups, or independent practice.
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