10.8
12% = 10% + 1% + 1%
10 percent of a number is that number but with the decimal point 1 to the left. 10% of 90.0 is 9.0
1% of a number is that number but with the decimal point two to the left. 1% of 90.0 is 0.9
9 + 0.9 + 0.9 = 10.8
10.8 is 12% of 90
