5.3 Solving Percent Problems

Tasha conducted a survey of the students in her school: From the results, Tasha calculated that 60% of the students go to school by bus. Liam knows that 450 students go to school by bus. How can Liam use these data to find the number of students in the school?

Tasha also found that 50% more students go by bus than walk or drive. About how many students walk or drive to school?

There are 3 types of percent problems: 1.Given the whole and a percent, find that percent of the whole. 2.Given part of the whole and its equivalent percent, find the whole. 3.Given part of the whole and the whole, write the part as a percent of the whole.

The grass is 30 cm tall. It grows by 40%. How tall is the grass now? Method 1: What is 40% of 30? 0.4 x 30 = 12 So the grass grows by 12cm. What’s the final height? = 42cm

Method 2: What is 140% of 30? 1.4 x 30 = 42cm You save a step this way.

A rabbit weighs 50lbs (he’s a heavy rabbit). He goes on a diet and loses 17% of his weight. What does he weigh now? Method 1: What is 17% of 50? 1.7 x 50 = 8.5 The rabbit loses 8.5lbs. What’s his new weight?50 – 8.5 = 41.5lbs

Method 2: What is 83% of his weight (50 lbs)? 0.83 x 50 = 41.5lbs