Your child brings home 46 + 27. You expect to see the numbers stacked in a column with a little 1 carried over. Instead the page shows 40 + 20 and 6 + 7, or a row of jumps along a line. You show the quick way you learned, and your child gets upset: "That's not how we do it at school!"
This happens in many families. This article explains why school may use different methods, how to help with homework without mixing them up, what to ask the teacher, and when it makes sense to share your own way.
Why school may teach a different way
Many schools today start with mental strategies and drawings, and bring in the written column method a little later. This varies a lot between countries, schools and teachers, so take it as a common pattern, not a rule.
The idea is to help children see what numbers are made of: tens and ones. A child who knows that 46 is four tens and six ones can understand why the column method works, and is more likely to notice when an answer looks wrong.
Both ways are correct. The column method is not old-fashioned, and the newer methods are not complicated for no reason. They are different paths up the same hill, and the answer at the top is the same.
Methods you might see on the homework
The names change from school to school, so ask your child what their class calls each one.
| Method | 46 + 27 done this way | What it helps your child see |
|---|---|---|
| Splitting numbers | 40 + 20 = 60, 6 + 7 = 13, 60 + 13 = 73 | Tens and ones are added separately |
| Jumps on a number line | Start at 46, jump 20 to 66, then 4 to 70, then 3 to 73 | Adding is moving along the numbers |
| Making a round number | 46 + 4 = 50, then 50 + 23 = 73 | Friendly numbers like 10 and 50 make sums easier |
| Drawing tens and ones | Sticks for tens, dots for ones; ten dots become one more stick | What "carrying" really means |
| Column method | Add the ones, carry the ten, add the tens | A quick written way, built on all of the above |
Subtraction has its own versions. For 52 − 17, a child might count up on a number line from 17 to 52 instead of taking away digit by digit.
Let your child be the teacher
The most useful thing you can say is: "Show me how you did it in class." Let your child explain, step by step, while you play the student. Explaining a method out loud is one of the best ways to understand it.
- Ask about each step: "What did you do first?", "Why did you split 27 into 20 and 7?", "Can you draw it?"
- If your child is stuck, look together at a worked example in the exercise book or textbook.
- If the method is new to you too, say so: "I learned this differently. Let's work it out together." Your child sees that adults also learn new things.
- Keep it short. If homework turns into tears, stop, and write a note to the teacher about where it went wrong.
Ask the teacher for a worked example
A short question to the teacher can save a lot of evenings. You might ask:
- For an example of how the class sets out the method, and the words they use for each step.
- When the column method usually comes, and whether it is fine to show it at home.
- Which part your child finds hard, and what the teacher suggests practising.
Telling the teacher where your child gets stuck at home is also useful for them. It shows what to explain again in class.
When and how to share your own way
Showing your method too early can confuse a child who is still learning the class method. They may mix steps from both, for example carrying a 1 in the middle of a number line. They may also feel they have to choose between you and the teacher.
So wait until your child is secure: they get the right answers with the class method and can explain how. Then:
- Call it "one more way", not "the right way" or "the quick way": "Here's another way I learned. Shall we see if it gives the same answer?"
- Do the same sum both ways and check that they land on the same answer. Talk about which one feels easier, and why.
- Show the link. The 1 you carry in the column method is the same as bundling ten dots into one stick in the drawing.
- Follow the class for schoolwork. If the teacher wants a particular method in homework or tests, your child uses that one there.
In Dologi's Math topic, puzzles like "Number line hops" ask where the rabbit lands, not which written method to use, so your child can get there in whatever way makes sense to them.
In short
- Many schools teach splitting, number lines and drawings before the column method. Both are correct.
- Ask your child to show you the class method, and play the student.
- Ask the teacher for a worked example and when the column method will come.
- Share your own method only once your child is secure, and call it "one more way".
Read more: What do children learn in primary maths? A map of skills by age and Mental maths to 20: simple strategies for adding and subtracting in your head.