My child can't memorize multiplication facts: the 21 that cause the trouble, and a way into each one

By 15Q20M Editorial · Last updated September 20, 2026

When a child can't memorize multiplication facts, the list is usually too long and too flat. Flipped pairs like 3 × 8 and 8 × 3 are one fact, and the 0s, 1s, 2s, 5s, and 10s come quickly for most kids. That leaves 21 harder facts, and each one can be built from a fact your child likely knows.

Why can't my child remember math facts?

A times table from 0 × 0 to 10 × 10 has 121 boxes. Handed over as one list, every box looks equally important and equally unrelated to the others. A child who is told to memorize it is being asked to store 121 separate sentences, and much of that practice lands on boxes that were never a problem.

Common Core asks for both strategies and memory. By the close of 3rd grade, students are expected to "know from memory all products of two one-digit numbers." The same standard pairs that fluency with "strategies such as the relationship between multiplication and division" and "properties of operations." A related standard, 3.OA.B.5, gives the examples. If 6 × 4 = 24 is known, then 4 × 6 = 24 is also known. And 8 × 7 can be found as 8 × 5 plus 8 × 2, which is 40 + 16 = 56.

So the standards expect facts to be learned through their relationships, with memory as the result. If your child has only met the facts as a list, there may be nothing to fall back on when one slips, and the only option left is to guess or count.

What are the hardest multiplication facts to memorize?

Start by crossing out what most children pick up early. The Maine Department of Education notes that students typically learn their 2s, 5s, and 10s first, and that they have been counting by those numbers since kindergarten. The 0s and 1s follow a rule. Cross out every row and column for 0, 1, 2, 5, and 10.

What remains uses only the numbers 3, 4, 6, 7, 8, and 9. That is a 6 by 6 block of 36 boxes. Since 3 × 8 and 8 × 3 are the same fact (teachers often call these turnarounds), the 36 boxes hold 21 different facts: 15 pairs plus the 6 squares.

The blank half of the table is the turnarounds. If the easier rows are secure, these 21 are the place to focus practice, and they keep coming up. In our Grade 4 workbook, about two thirds of the multi-digit products a student has to compute have at least one of them inside.

A 5-minute sort: which of the 21 is your child missing?

1. Write these 21 facts on index cards or slips of paper, one per card, with no answers: 3 × 3, 3 × 4, 3 × 6, 3 × 7, 3 × 8, 3 × 9, 4 × 4, 4 × 6, 4 × 7, 4 × 8, 4 × 9, 6 × 6, 6 × 7, 6 × 8, 6 × 9, 7 × 7, 7 × 8, 7 × 9, 8 × 8, 8 × 9, 9 × 9. Shuffle them so they are out of table order.
2. Show one card at a time and have your child say the answer out loud. Keep it untimed and relaxed. You are sorting, and your child should know that nothing is being graded.
3. Make three piles. Pile 1: answered right away. Pile 2: correct, but your child counted up, used fingers, or worked it out. Pile 3: wrong, or stuck.
4. Stop when the cards run out. Twenty-one cards take about five minutes.

Pile 1 needs nothing more. Pile 2 is correct and not yet automatic, so it may need a faster route plus short, regular practice recalling the answer. Pile 3 is the real list, and it is usually much shorter than 21. One sort is a snapshot, so repeat it a few days later before deciding which facts are truly missing.

Multiplication facts strategies: a route into each of the 21

Each strategy below starts from a fact in the easy set and builds up. Maine's guidance calls these helper facts: to solve 6 × 7, a student who knows 5 × 7 = 35 needs "one additional group of 7" to get 42. Doubling works the same way. Since 2 × 9 = 18 is half of 4 × 9, the student doubles 18 to get 36.

Each fact appears once, under the route that is usually easiest, and the six rows add up to 21. A child who knows the easy set and these moves can rebuild any of the 21.

A strategy is a way back to a fact until recall is instant, and the goal is still to know the fact from memory. A route gives your child something to try when memory slips, so a blank moment does not have to end in a guess.

How to help your child memorize multiplication facts from here

Work on two or three cards from pile 3 at a time. Teach the route for each one, have your child say it out loud a few times, and then mix those cards in with pile 1 cards so that most answers in a session are wins.

Bring in the turnaround and the division once the fact feels solid. If 6 × 8 = 48 is the fact of the day, ask 8 × 6 next, then 48 ÷ 6 and 48 ÷ 8. The standard ties fluency to the relationship between multiplication and division, and the four questions belong to one fact family.

Our own working rule, not a standard: move a card to pile 1 after your child answers it right away on three different days. One good evening may not last.

Keep sessions short and frequent. Our guide on math facts fluency covers session length, timed practice, and how to tell a facts gap from trouble with the multi-digit steps.

Math facts fluency in 4th grade: is it the facts or the steps?

How long does it take to memorize multiplication tables?

We have not found a reliable number of weeks to quote, and the honest answer depends on the size of pile 3. A child with four missing facts and a child with fourteen are on different timelines, which is the reason to sort before you start. Re-sort every week or two and watch pile 3 shrink. That tells you more than a target date does.

If pile 3 is not shrinking after several weeks of short, regular sessions, bring the dated piles to the teacher. Our fluency guide covers that conversation, and a home check cannot diagnose a learning difference.

Facts are one layer. In 4th grade they sit inside area models, multi-digit multiplication, and long division, where a single slow fact can stall a whole problem. Our daily sets mix those problem types on paper, 15 a day, and the free app scores them and explains each miss.

See the Grade 4 workbook on Amazon

Where the facts get used next: the area model in 4th grade

Why long division is so hard, and how slow facts stall it

If it's more than facts: my 4th grader is struggling with math

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