Balance subtraction equations – up to 18
key notes :
How do you balance two equations in maths?
Step 1) Find the value of the side of the equation without any missing numbers.
Step 2) Make sure the value on the other side of the equation is equal to this value.
Learn with an example
Which number makes the equation true?
6 − 4 = 3 − ?
First, subtract 6 − 4:
6 – 4 =3 – ?
2 = 3 – ?
Now decide which number makes the subtraction number sentence true. You can think of a subtraction fact you know, or you can subtract to find the answer.
The subtraction fact is:
3 − 1 = 2
Did you remember this subtraction fact? If not, you can find the answer by subtracting.
Subtract:
3 − 2 = 1
The missing number is 1.
Which number makes the equation true?
___− 4 = 3 − 1
First, subtract 3 − 1:
? – 4 = 3 – 1
? – 4 = 2
Now decide which number makes the subtraction number sentence true. You can think of a subtraction fact you know, or you can add to find the answer.
The subtraction fact is:
6 − 4 = 2
Did you remember this subtraction fact? If not, you can find the answer by adding.
Add:
2 + 4 = 6
The missing number is 6.
Which number makes the equation true?
3 − 3 = ___ − 4
First, subtract 3 − 3:
3 − 3 = ? − 4
0 = ? − 4
Now decide which number makes the subtraction number sentence true. You can think of a subtraction fact you know, or you can add to find the answer.
The subtraction fact is:
4 − 4 = 0
Did you remember this subtraction fact? If not, you can find the answer by adding.
Add:
0 + 4 = 4
The missing number is 4.
Let’s practice!🖊️
