+ 8
For rough, by-hand computations I think. It is relatively easier for human brain to stay within small numbers threshold, especially when multiplying and dividing.
Computers don't care ;)
https://code.sololearn.com/czBAt7x8pBAm/?ref=app
https://code.sololearn.com/cK93Tvd2ZXKY/?ref=app
https://code.sololearn.com/cvc6WGjeKz70/?ref=app