Year 8: Find the total based on a ratio

This cheat sheet will help you find the total amount when given a ratio.

Understanding ratios

A ratio compares two amounts. It's usually written as a colon (:) between the numbers, like 2:3 or 1:4.

How tofind the total

1. Find the Total Ratio: Add up all the numbers in the ratio.

2. Example:

   If the ratio is 2:3:5, add $2+3+5=10$
3. Calculate the Value: Determine what one 'unit' in the ratio represents.

4. Example:

   If the total ratio is 10 and the ratio is 2:3:5, then one 'unit' is 1 (because 10 / 10 = 1).
5. Calculate the Total Amount: Multiply the 'unit' by each number in the ratio.

6. Example:

   $1\times 2=2$, $1\times 3=3$, $1\times 5=5$. Therefore, the total is $2+3+5=10$.

Another example

If a recipe calls for a ratio of Flour:Sugar:Eggs = 3:2:1

Total Ratio = $3+2+1=6$

One unit = $1(6/6=1)$

Ingredients: $3\times 1=3$ cups of flour, $2\times 1=2$ cups of sugar, $1\times 1=1$ egg.