Primary 2 · Mathematics
P2 multiplication tables of 3 and 4
Knowing 5 × 6 = 30 is a good way into 4 × 6, as long as the right amount comes off. Lift one row of coins off the table, not four coins, and the new fact is 24.
- Level
- P2
- Usually taught
- Term 3
- Covers
- 1 concept
What changes at P2
In Primary 2, a term after the 2, 5 and 10 times tables, your child learns the 3 and 4 times tables. Schools teach them as facts to build, not only to recite: 3 × 8 is double 8 and one more 8, and 4 × 7 is double 7, doubled again.
The idea underneath is one group. 4 × 6 is 4 groups of 6, so going from 5 × 6 to 4 × 6 takes away one whole group of 6, not 4.
The sentence that costs the mark
Use 5 × 6 = 30 to find 4 × 6.
What the working usually does
4 × 6 = 30 −4=26
Takes away 4, the number in the new fact.
What the question asked
4 × 6 = 30 −one group of 6=24
Takes away one whole group, which is 6.
Starting from a fact already known is exactly what schools teach, and 30 − 4 is worked out correctly. The slip is in what one group is worth, and 26 sits close enough to 24 to pass a quick look.
| Group | Detail |
|---|---|
| 24 | |
| 6 |
The same question, worked properly
Start from a fact you know
5 × 6 = 305 groups of 6. Drawn as an array, that is 5 rows of 6.
Take away one whole group
4 × 6 is one group of 6 fewerThis is the step that fails. Going from 5 groups to 4 removes a whole row, which is 6, not 4. Taking away the 4 in the question is the slip.
Subtract the group
30 − 6 = 24So 4 × 6 = 24. A quick check from the doubles: double 6 is 12, and double 12 is 24.
How can you tell it has clicked?
Ask how your child would find 4 × 7 from 5 × 7 = 35. "Take away 7" means they see the groups. "Take away 4" means the number in the question is doing the work instead.
Then try 3 × 8 from 2 × 8 = 16. A child who adds one more 8 has the same idea running the other way.
One thing to try tonight
Build 5 rows of 6 coins, then lift one whole row off the table and count what is left.
Do the same for 3 × 7: make 2 rows of 7, then add one more row. The coins turn "one group" into something your child can pick up.
What your child will meet in this topic
- Times Tables of 3 and 4
Most Singapore schools introduce this in Term 3, though schools do differ by a term either way. If your child’s school runs a different order, you can set it in the schedule on your dashboard.
What it leads to
P3 finishes the tables with 6, 7, 8 and 9, and the same move does much of the work: 6 × 7 is 5 × 7 and one more 7.
Division within the tables uses these facts too. 24 ÷ 4 is answered by the 4 times table, not by counting.
The same topic in other years
It comes back each year and gets harder, so it helps to see what came before and what is coming.
More in Primary 2
Other topics in the same year, so you can see what sits either side of this one.
See how your child is doing on this topic
StudyLah marks each step separately, so you can see whether it was the setup or the arithmetic that cost the mark.