Using doubling or halving to calculate efficiently

Maths

To multiply by 4, you can double and double again.

To divide by 4, you can halve then halve again.

To multiply by 8 you can multiply by 2, 3 times.  This is the same as multiplying by 6.

If you change the order of factors and the product will change too.

You can change the order of factors and the product will be the same.

What is the commutative law in multiplication?

You can multiply more than two factors in any order and the product will be the same.

You can multiply three factors in a certain order.

You should not multiply more than two factors.

What is the associative law in multiplication?

Which law do you use when multiplying 2 x 5 x 6?

When multiplying 6 x 2 x 5, which is the most efficient order?