How do you calculate 180*1.15 in your head without a calculator?
I have search for this thing for 30 minutes and still no answer.
180 x 1.15 =
Start with a 1 to the left of the decimal in 1.15. Multiply that 1 x 180 =180
Then continue with 1 to the right of the decimal x 180/10 =18 + 180 =198
Then continue with 5 to the right of the decimal x 180/100 =900/100=9 +198 =207
Or look at it as 100% of 180 + 10% of 180 + 5% of 180
100% of 180 = 180
10% of 180 = 18
5% of 180 = Half of 10% of 180 = 18/2 = 9
180+18+9 = 207
