To estimate the percent of a number, start by rounding the percent. Then write the rounded percent as a fraction and multiply by the number.
B
Start by finding how many minutes there are in a day.
A
About 3.6 hours, see solution.
B
about 112 minutes
Practice makes perfect
We want to find about how many more hours Avery spends sleeping than doing the activities in the other category of her chart. According to the given diagram, Avery spends 33 % of their day sleeping and 19 % of their day doing the activities in the other category. Let's start by calculating the difference between the percents.
33 % -19 % = 14 %
To find how many more hours Avery spends sleeping than doing the activities in the other category, we need to find 14 % of 24 hours. Let's start by rounding the percent.
14 %of 24h ≈ 15 %of 24hWe can find 15 % of 24 hours by multiplying 15 % by 24 hours.
15 %of 24h = 15 %* 24h
Before we perform the multiplication, we will write the rounded percent as a fraction and reduce it to its simplest form. We can write a percent as a fraction by writing the number part as a numerator over 100.
We found that 15 % is equal to 320.
15 %* 24h = 3/20* 24h
Finally, let's perform the multiplication to get our estimation. We can ignore the units for the moment to keep our calculations simple.
We found that Avery spends about 3.6 hours more sleeping than they do doing the activities in the "other" category.
We want to find how many minutes Avery spends each day on extracurricular activities. We are given that Avery spends 8 % of each day on these activities. Let's start by finding how many minutes there are in a day. Remember that there are 60 minutes in an hour and 24 hours in a day. We can use this information to write the following proportion.
1hour/60minutes=24hours/xminutes
Let's solve the proportion for x using cross products. We can ignore the units for now.
We got that x=1440 is the solution to the proportion. This means that there are 1440 minutes in 24 hours. Now we will find 8 % of 1440 minutes. Let's start by rounding the number of minutes.
8 %of 1440 ≈ 8 %of 1400
Before we can calculate 8 % of 1400, let's first find 1 % of 1400 by multiplying these two quantities. Recall that 1 % is equal to 0.01. To multiply a number by 1 %, we can move the decimal point two places to the left.
We found that 1 % of 1400 is equal to 14. Since 8 % is 8* 1 %, 8 % of 1400 is equal to 8* 14.
8 %of 1400 = 8* 14 = 112
Avery spends about 112 minutes each day on extracurricular activities.
