Question

Explain how using basic facts can help you find 10x20x30x40 mentally

Answer 1

you take off the zeros at the end of all the numbers and multiply 1,2,3,  and 4 and then add the zeros at the end so you get 24 then adding the zeros you get 240000

Answer 2

Using basic facts can help find the equation mentally. We can do 1 × 2 = 2, then 2 × 3 = 6, then 6 × 4 = 24. Then just add the 0 to 24 to get the answer, 240,000.