118k views
4 votes
Is there a fast way to figure out 197 times 4 in mental math

User DaWilli
by
7.4k points

2 Answers

5 votes
I would multiply each from right to left, and when I got and answer for the first digit, ex: 7*4=28
I would keep in mind that there is a 2 I have to add, and just trace out 8 in my palm with my finger, or just mentally in my mind.
Continue to do it for the rest of them, and you will get your answer.
Hope this helps.
User Victor
by
6.8k points
1 vote
you can try taking apart the problem and doing this
4x7=28
4x90=360
4x100=400
add them up
and you get 788
srry if too complicated answer
User Constantin Guay
by
6.9k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.