Explain how to use mental math to find the product of 64 and 24

First multiply the 2 fours. 

4 multiplied by 4 is 16.

6 will be your first number, and just remember in your brain 1. I hold a 1 on my hand to remember.

6 multiplied by 2 is 12, add one and you get 13.

136 will be your answer.

Hope this helped, and please mark brainliest! :)