The times tables of 1, 2, 5 and 10 are the key facts.
With them, you can also work out hard multiplication problems easily.
Example: 7 × 6 is hard, but:
5 × 6 = 30 (key fact), 2 × 6 = 12
Together: 30 + 12 = 42, so 7 × 6 = 42
Tip: Split the hard number into a key number plus the rest.
The numbers filled in show the solution.
Example
- 42,30,12,42
For parents
What does this exercise practice?
Key facts help derive hard times-table problems from easy ones.
Common pitfalls
Some children try to memorize everything, which is a lot more work. Splitting the number is the faster way.
How to practice at home
Try it: 6 × 8 = 5 × 8 + 1 × 8 = 40 + 8 = 48.
Related: Multiply, Times array, Semi-written multiplication