Addition and Subtraction Practice: A Step-by-Step Guide for Parents

Addition and subtraction are the first maths a child meets that they will use every single day for the rest of their life. They are also where most primary maths difficulties start — not because the operations are hard, but because it is easy to get an answer right for the wrong reason, and easy for a small gap to stay hidden for a year.

This guide covers what to practise at each stage, the specific mistakes worth catching, and how to help in a way that builds independence rather than dependence.

What to practise, by age

Ages 6–7: facts within 20

The goal is not speed yet. It is knowing that 7 + 5 is 12 without rebuilding it from scratch each time, and understanding that subtraction has two meanings — taking away, and finding the difference.

• Number bonds to 10, then to 20
• Adding and subtracting with objects, pictures and a number line
• Counting on from the larger number rather than counting everything again
• Simple one-step word problems

Ages 7–8: written methods and regrouping

Numbers reach 1,000 and the informal strategies stop scaling. This is where column addition and subtraction arrive, along with carrying and borrowing.

• Column addition and subtraction with two- and three-digit numbers
• Regrouping, understood rather than performed
• Mental strategies for adding and subtracting near-round numbers
• Two-step word problems

Ages 8–9: bigger numbers, reliable methods

Three- and four-digit numbers, and a written method that works every time.

• Column methods with regrouping across several columns
• Estimating before calculating, to check whether an answer is plausible
• Using the inverse operation to check the result

Ages 9–11: fluency and application

The operations themselves stop being the challenge. What matters now is choosing the right one and staying accurate with large numbers.

• Addition and subtraction beyond 10,000, and into the millions
• Multi-step problems combining both operations
• Deciding between mental and written methods and explaining the choice

The four mistakes worth catching

Most difficulty traces back to a small number of specific gaps. These are the ones worth looking for.

Counting all instead of counting on

Asked for 8 + 3, a child starts at one and counts all eleven. The answer is right, so it passes unnoticed — but it means the number facts are not yet known, only reconstructed. Watch how the answer is produced, not just whether it is correct.

Regrouping as a ritual

A child can carry perfectly and still not know that the small 1 means ten. Ask what it is worth. If the answer is "one", the method is memorised and will fail the moment a problem looks unfamiliar.

Subtracting across zeros

Something like 3,004 − 1,287 breaks anyone who learned borrowing as a one-step rule, because the borrowing has to travel through two empty columns. This single pattern accounts for a large share of subtraction errors at ages 8 to 10 and is worth practising on its own.

Subtraction as take-away only

If subtraction always means removing things, "how many more does Ana need?" stops looking like subtraction. Introduce difference questions early, so the operation has both meanings from the start.

How to help without taking over

The instinct when a child stalls is to explain. It is almost always better to wait, then ask a question instead.

• **Ask "how did you work that out?"** — including when the answer is right. It is the fastest way to tell whether a correct answer came from understanding or from luck.
• **Wait longer than feels comfortable.** Most children self-correct if given a few extra seconds. Stepping in early teaches them that hesitation summons help.
• **Let them be wrong all the way to the end.** A completed wrong answer is something you can look at together. An interrupted one teaches nothing.
• **Mark it together, not for them.** Going through the answers side by side turns correction into a conversation instead of a verdict.

How much practice, and how often

Ten to fifteen minutes on most days beats an hour at the weekend, and it is not close. Number facts fade without regular use, and short sessions keep them fresh without turning maths into an ordeal. If a session turns into an argument, stop and come back tomorrow — a child's belief about whether they are "good at maths" is being formed at this age, and it is worth more than any single worksheet.

A reasonable weekly rhythm looks like this: four short practice sessions, one of them on paper, one as a game, and the rest online or mental. Variety matters less than regularity, but it does help.

Practising with PetMat

If you want structured practice that follows this sequence, every year is broken into modules on the learn hubs — addition and subtraction is usually the largest one. Each module page lists the sub-topics in order, so you can find the specific skill your child is stuck on rather than working through everything.

For paper practice, the free printable worksheets give you a ready-made sheet with a full answer key, no account needed. And if your child resists worksheets entirely, the addition and subtraction exercise covers the same facts with a score attached instead of a page, and Number Catcher turns recall into a game.

The right amount of any of these is however much your child will actually do without a fight. Ten minutes, most days, is the whole strategy.