5.402 x 3.8 = 20.5276
First, move the decimal over to the right 3xs for 5.402 and 1x for 3.8
Second, multiply
5402 x 38 = 205247
Then, once you get you answer move the decimal starting from the right behind the 7 4xs to the front, because thats how many times you moved the decimal with both numbers 5.402 (3xs) and 3.8 (1x). 3 + 1 = 4
Last, you get 20.527 for your answer
I hate math, but hope this helps, sorry if not tho