Subtraction means taking some away to find how many are left. If you have some cookies and eat a few, subtraction tells you how many remain. This lesson shows taking away with pictures, then the quick way to count back.
When we subtract, we take some things away and count what is left. The minus sign − means 'take away'. So 5 − 2 means 'five things, take away two', and it leaves 3.
In the picture, we start with five dots and cross out two of them. Count the dots that are not crossed out — there are three left.
Here is a story to make it real. Mia is holding 5 balloons at a party. Suddenly, 2 balloons float away into the sky! How many balloons does Mia have left?
We start with 5 and take away the 2 that flew off. Cross off 2 balloons and count the ones still in her hand: 3 balloons are left. That is exactly 5 − 2 = 3. Taking-away stories — eating cookies, balloons floating off, toys put away — are a fun way to practise subtraction.
Just like adding has 'counting on', subtracting has counting back. Start at the first number and count backwards by the second number. For 7 − 3, start at 7 and count back three: 6, 5, 4. The answer is 4.
Your fingers help here too: hold up the big number, then put down one finger for each number you take away, and count what is left standing.
Subtraction undoes addition. If 3 + 2 = 5, then 5 − 2 = 3 — taking the 2 back away returns you to 3. They are opposite operations, like walking forward and then walking back.
This is why knowing your adding facts helps with subtraction: if you know 4 + 3 = 7, you also know 7 − 3 = 4. Every adding fact you learn quietly gives you a subtracting fact for free, so practising one really helps the other.
Try these. Pick an answer to see whether it's right and why.