# How can GCF be used in real life?

##### 1 Answer

We can use it for simplifying fractions or ratios!

#### Explanation:

We use greatest common factors all the time with fractions, and as fractions are used a lot in everyday life, this makes GCF very useful!

By finding the GCF of the denominator and numerator, you can then successfully simplify a fraction or ratio.

E.g. We can simplify

Then we divide both parts by the HCF to simplify.

It also works for ratios, where you can simplify each side using HCF to find out a

So, to put this into a situation, say you know that for every 5 people at a party, you need 15 sandwiches. The HCF of these two numbers is 5, so for each person you need:

3 sandwiches.

Now, if 16 people come to your party, you know you have to make

A final example is with recipes.

This is a very useful time for maths to get involved!

Here is a recipe for a 10 cupcakes and their ratios related to the serving size :

100g flour = 10 people:100g = 1:10

80g sugar = 10 people:80g = 1:8

50g butter = 10 people:50g = 1:5

2 eggs = 10 people:2 eggs = 1:0.2 eggs

So, if we want to give cakes to all our friends, and need 25 cupcakes (what a popular mathematician!) then you can just multiply out this ratio.

Flour = 1:10 = 25:250

80g sugar = 1:8 = 1:200

50g butter = 1:5 = 25:125

2 eggs = 1:0.2 eggs = 25:5

Hope this helps; let me know if I can do anything else:)