Lesson 4 — Activity 3: Fractions at Home



Getting Ready


There are other ways that you will use fractions at home in your daily life. Other than recipes, which we looked at in the previous activity, you will find that there are many other places where it will be important for you to know how to work with fractions.

Courtesy of Getty

There are some jobs we do around our home that require us to understand fractions. For example, when you need to mix plant fertilizer, you need to think about fractions.

In order to water 20 outdoor plants, follow these instructions to mix fertilizer:


Courtesy of Getty

1/3 cup nitrogen
1/8 cup phosphorous
5 cups water


Here is the problem though — there are about 60 outdoor plants to water. That means you need three times the amount of fertilizer mix.

How will you make three times more fertilizer? You need to increase each amount three times. You can do that by adding the fractions three times as follows:


1/3 + 1/3 + 1/3 = 3/3 = 1 cup of nitrogen
1/8 + 1/8 + 1/8 = 3/8 cup of phosphorous
5 + 5 + 5 = 15 cups of water

Therefore you need 1 cup of nitrogen, 3/8 cup of phosphorous, and 15 cups of water to make fertilizer for 60 outdoor plants.

In the example above, you could also multiply the fractions by 3 instead of adding the fractions three times.


Let's look at a quick review of how to multiply fractions.


So, in the example above, if we multiplied the fractions by 3, it would like like this:



Courtesy of ADLC


The amounts are the same!


  Self-check!

Try this!


Try this activity to learn more about working with fractions when mixing cement for new front steps. Answer these questions on your own first. When you are finished, click on the tabs below to check your answers.


We want to make half of the following cement mix recipe:

  • 1 bucket of sand

  • «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mn mathcolor=¨#FFFFFF¨»2«/mn»«mstyle displaystyle=¨false¨»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»2«/mn»«/mfrac»«/mstyle»«/math» buckets of gravel

  • «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mn mathcolor=¨#FFFFFF¨»4«/mn»«mstyle displaystyle=¨false¨»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»2«/mn»«/mfrac»«/mstyle»«/math» buckets of cement

  • 10 buckets of water


What is half of 1 bucket of sand?

Half would be «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»2«/mn»«/mfrac»«/math» a bucket of sand


What is half of «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mn mathcolor=¨#FFFFFF¨»2«/mn»«mo mathcolor=¨#FFFFFF¨»§#160;«/mo»«mstyle displaystyle=¨false¨»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»2«/mn»«/mfrac»«/mstyle»«/math» buckets of gravel?

Half would be «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mn mathcolor=¨#FFFFFF¨»1«/mn»«mstyle displaystyle=¨false¨»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»4«/mn»«/mfrac»«/mstyle»«/math» buckets of gravel (half of 2 = 1 and half of «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»2«/mn»«/mfrac»«mo mathcolor=¨#FFFFFF¨»§#160;«/mo»«mo mathcolor=¨#FFFFFF¨»=«/mo»«mo mathcolor=¨#FFFFFF¨»§#160;«/mo»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»4«/mn»«/mfrac»«/math»).


What is half of «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mn mathcolor=¨#FFFFFF¨»4«/mn»«mstyle displaystyle=¨false¨»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»2«/mn»«/mfrac»«/mstyle»«/math» buckets of cement?

Half would be «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mn mathcolor=¨#FFFFFF¨»2«/mn»«mstyle displaystyle=¨false¨»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»4«/mn»«/mfrac»«/mstyle»«/math» buckets of cement mix (half of 4 = 2 and half of «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»2«/mn»«/mfrac»«mo mathcolor=¨#FFFFFF¨»§#160;«/mo»«mo mathcolor=¨#FFFFFF¨»=«/mo»«mo mathcolor=¨#FFFFFF¨»§#160;«/mo»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»4«/mn»«/mfrac»«/math»).


What is half of 10 buckets of water?

Half would be 5 buckets of water


Therefore, what is the recipe if we want to make half of cement mix?

  • «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»2«/mn»«/mfrac»«/math» bucket of sand, 
  • «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mn mathcolor=¨#FFFFFF¨»1«/mn»«mstyle displaystyle=¨false¨»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»4«/mn»«/mfrac»«/mstyle»«/math» buckets of gravel, 
  • «math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«mn mathcolor=¨#FFFFFF¨»2«/mn»«mstyle displaystyle=¨false¨»«mfrac bevelled=¨true¨ mathcolor=¨#FFFFFF¨»«mn»1«/mn»«mn»4«/mn»«/mfrac»«/mstyle»«/math» buckets of cement mix,
  • 5 buckets of water