Elementary mathematics builds in a fairly strict order: counting leads to addition, addition to multiplication, and multiplication to fractions and division. A gap early on tends to show up as difficulty much later.

This is why apparent difficulty with fractions in grade four is so often really a gap in multiplication from grade two. Checking backwards is usually more productive than practising the topic a child is currently stuck on.

How the topics connect

Addition and subtraction come first, and need to become automatic before what follows.
Multiplication builds directly on addition, and division builds on multiplication.
Fractions depend on division and on the idea of equal parts, which is why they cause so much trouble.
Geometry runs alongside the rest and often suits children who find arithmetic harder.

Supporting a child in maths

If a topic is not going in, check the one below it. Most difficulties are gaps in earlier material rather than the current topic.
Practise number facts in short daily bursts. Fluency frees up attention for the actual problem.
Ask how the child worked something out, not just what the answer was. The method reveals the misunderstanding.
Avoid saying you were bad at maths. Children pick up the idea that mathematical ability is fixed, and it affects how they respond to difficulty.

Frequently asked questions

What maths should a child know by the end of elementary school?

Broadly: fluent addition, subtraction, multiplication and division, a working understanding of fractions and decimals, and familiarity with shapes, measurement, and simple data.

My child is struggling with fractions. What should I do?

Check multiplication and division first. Fractions depend on both, and difficulty with fractions is frequently a gap in earlier material rather than the fractions themselves.

How much maths practice is useful per day?

Ten to fifteen minutes of focused practice daily is more effective than long occasional sessions, because number fact recall builds through frequent retrieval.