Subtraction up to 10
By the end of this lesson a child subtracts a number that is no bigger than the one they start from, up to 10, and checks the result by counting back. Subtraction takes things out of a group.
What the child can do at the end
- Read − as “take away” and = as “leaves”.
- For 5 − 2, start at 5 and count back only the ones taken away: 4, 3.
- Know that 5 − 0 = 5 and that 5 − 5 = 0.
What subtraction means
If there are 5 apples and 2 are eaten, the question is how many are left. The sentence 5 − 2 = 3 says: start at 5, take away 2, and 3 remain.
One problem, step by step
There are 5 biscuits on a plate. The child eats 2. How many are left?
- The first number is what was there: 5.
- The second number is what is taken away: 2.
- Write 5 − 2.
- Five is already there. Count back only the ones eaten: 4, 3.
- 3 are left. Check: put down 5 biscuits, remove 2, and count what remains.
A common mistake
For 5 − 2 the child says “5, 4” and stops at 4. They counted the five itself, so they took away only one instead of two. Five is already there. Count only what is eaten: 4, 3.
The other slip is zero. 5 − 0 means nothing is taken away, so 5 remains. 5 − 5 means everything is taken away, so 0 remains, not 5.
Practice
Start at the first number and count back only as many as the second number says.
- 4 − 1 = ___
- 6 − 2 = ___
- 8 − 3 = ___
- 7 − 7 = ___
- 9 − 0 = ___
- 10 − 4 = ___
In words: a box has 6 pencils, then 2 are taken out. How many are left?
Answers
- 3
- 4
- 5
- 0
- 9
- 6
Pencils: 6 − 2 = 4. From 6, count back twice: 5, 4.
Say 7 − 7 out loud. Everything that was there is taken away, so nothing remains. The answer is 0.
After the lesson, the quiz
When the list is done without looking at the answers, open the subtraction quiz. The subtraction table shows every difference up to 10 in one place.
Subtraction quiz Subtraction table
For a parent
Let the child physically remove the objects, not only say a number. If they stop, ask “how many did you take away”, not “what is the right answer”.