Exercise 5 Page 358

We want to estimate 47 % of 77. We will start by rounding each number. c|c 47is closer to50 & 77is closer to80 than to40 & than to70 ⇓ & ⇓ 47 % ≈ 50 % & 77≈ 80Now we multiply the rounded numbers to get an estimation. First, we write the percent as a fraction.

50 %* 80

WriteAsFrac

Write as a fraction

50/100 * 80

ReduceFrac

a/b=.a / 50./.b / 50.

50÷ 50/100÷ 50 * 80

CalcQuot

Calculate quotient

1/2 * 80

MoveRightFacToNumOne

1/b* a = a/b

80/2

CalcQuot

Calculate quotient

40

Now we are ready to complete the exercise. 47 % ≈ 50 % 77 ≈ 80 50 % of 80 = 40 We found that 47 % of 77 is about 40.