Ratios and Rates

What is rate?

A rate is an ordered comparison of quantities of different kinds.

What is a Ratio?

A ratio is an ordered comparison of quantities of the same kind.

Comparing prices

A unit cost looks at the cost per one. To get a unit cost, I set up a ratio with the price in the numerator and the other measure in the denominator. I divide to get the cost per one gram, metre, litre, kg....

Unit Rate Examples

If a cleaner works for 4 hours and receives $48, what is his rate of pay? His rate of pay is $12/hour If he worked 40 hours how much will he be paid? If the cleaner was paid $102, how many hours did he work?

Ratio example

If you baked a cake and the instruction was 3:7 icing and batter. there would be 3 equal parts of icing and 7 equal parts of batter.

How are Ratios written?

Ratios are written without units. EX 1:2

Ratios in simplest form

Ratios can be reduced.

Ratios can be written in three different ways.

Ratios can be written in three different ways. Fraction-like, using a colon or using the word "TO" in between.

Unit Rates

To help compare things often we use unit rates. A unit rate is a ratio which compares a number and measure to one of another measure. much will he be paid? If the cleaner was paid $102, how many hours did he work?

How are Rates written.

Unlike ratios rates are written with measurements.

Comparing prices example

Which box of Dove detergent gives better value for money. A 500g costing $3.50 or B 750g costing $5.40.