Caroline needs to find 15% of $128, but she doesn't have a calculator. Thoroughly explain how she can do this mentally, detailing each step. Give the final answer.
Mathematics · High School · Mon Jan 18 2021
Answered on
Given the statement:
Caroline needs to find 15% of $128, but she doesn't have a calculator
Solve mentally.
Solution:
In order to determine 15% of $128, we simply need to multiply 15 by 8, then multiply 15 by 20, then 15 by 100.
= 15 (8)
=120
= 15 (20)
=300
= 15(100)
= 1500
Add the values together.
= 120 + 300 + 1500
= 1920
Move to decimal places to the right to the left in order to determine the final answer.
= 19.2
Final answer:
= 19.2