Week of November 16-20, 2015

Falcons,

This is the last school week before Thanksgiving break so let's stay focused and on task. We will begin working with ratios and rates. The good news is that rates may help some of you make a better buy during the sales going on through Thanksgiving Break, now this is when you know math pays off!

Ratios

A ratio compares values.

A ratio says how much of one thing there is compared to another thing.

There are 3 blue squares to 1 yellow square

Ratios can be shown in different ways:

Using the ":" to separate the values:		3 : 1
Instead of the ":" we can use the word "to":		3 to 1
Or write it like a fraction:		3 1

A ratio can be scaled up:

Here the ratio is also 3 blue squares to 1 yellow square,
even though there are more squares.

Using Ratios

The trick with ratios is to always multiply or divide the numbers by the same value.

Example:

4 : 5 is the same as 4×2 : 5×2 = 8 : 10

Recipes

Example: A Recipe for pancakes uses 3 cups of flour and 2 cups of milk.

So the ratio of flour to milk is 3 : 2

To make pancakes for a LOT of people we might need 4 times the quantity, so we multiply the numbers by 4:

3×4 : 2×4 = 12 : 8

In other words, 12 cups of flour and 8 cups of milk.

The ratio is still the same, so the pancakes should be just as yummy.