Answer:
7.956
Step-by-step explanation:
10.2*0.78 can be rewritten as 102*78*0.001. I'd split this even further, since I'm doing it in my head, into (100*78+2*78)*0.001. One step at a time.
100*78=7800
2*78=140+16=156
7800+156=7856+100=7956
7956*0.001=7.956, which is the answer, and is confirmed by a calculator
