Percent of a number

Percent of a number

In this section, we will try to estimate the percent of a number without using a calculator. The trick is to breakdown the percent into smaller percent first. These smaller percentages are easier for mental calculation.

Lessons

  • 1.
    Evaluate without using a calculator. Then, check your answers with a calculator.
    a)
    15% of 40

    b)
    320% of 600

    c)
    17.5% of 20

    d)
    201420\frac{1}{4}% of 50


  • 2.
    The total rain precipitation of last summer was 350 mm. If it increased by 121212\frac{1}{2}% this summer, what was the rain precipitation this summer?

Do better in math today
3.
Introduction to Ratios, and Percentages
3.1
Percent of a number
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