The facts of 2, 5 and 10 are your building blocks. The 3s, 4s and 6s are built from them, so you never have to start from scratch.
Why it works
4 groups is 2 groups and 2 more groups, so a 4s fact is a 2s fact doubled. 3 groups is 2 groups and 1 more. 6 groups is 5 groups and 1 more. Splitting the groups never changes the total.
| To find | Think | Example |
|---|---|---|
| $3 \times n$ | double $n$, then add one more $n$ | $3 \times 8 = 16 + 8 = 24$ |
| $4 \times n$ | double, then double again | $4 \times 7 = 14 + 14 = 28$ |
| $6 \times n$ | $5 \times n$, then one more $n$ | $6 \times 7 = 35 + 7 = 42$ |
Key idea
Build hard facts from easy ones: 4s are double 2s; 3s are 2s plus one group; 6s are 5s plus one group.
Worked example: Double, double
Find $4 \times 6$.
- $2 \times 6 = 12$.
- Double it: $12 + 12 = 24$.
Answer: $24$
Worked example: Five and one more
Find $6 \times 8$.
- $5 \times 8 = 40$.
- One more group of 8: $40 + 8 = 48$.
Answer: $48$
Common mistake
Adding 1 instead of one more group. $6 \times 8$ is not $40 + 1$. "One more group" means one more 8, so it is $40 + 8 = 48$.