Explain how you can use doubles when multiplying with 4 to find 4 times 8

Multiplying by 4 using the doubles strategy utilizes the fact that 4 is double of 2. Hence, 4 time any number is double of 2 times that number.

Thus, given 4 x 8, it can be evaluated using the double strategy as follows 2 x 8 + 2 x 8 = 16 + 16 = 32.