## Friday, October 30, 2009

### Celdrick's Rate Growing Post

Ratio:A ratio is an expression that compares quantities relative to each other. The most common examples involve two quantities, but any number of quantities can be compared. Ratios are represented mathematically by separating each quantity with a colon – for example, the ratio 2:3, which is read as the ratio "two to three". The quantities separated by colons are sometimes called terms.

Rate:In mathematics, a rate is a ratio between two measurements, often with different units. If the unit or quantity in respect of which something is changing is not specified, usually the rate is per unit time. However, a rate of change can be specified per unit time, or per unit of length or mass or another quantity. The most common type of rate is "per unit time", such as speed, heart rate and flux. Rates that have a non-time denominator include exchange rates, literacy rates and electric flux.

In describing the units of a rate, the word "per" is used to separate the units of the two measurements used to calculate the rate (for example a heart rate is expressed "beats per minute"). A rate defined using two numbers of the same units (such as tax rates) or counts (such as literacy rate) will result in a dimensionless quantity, which can be expressed as a percentage (for example, the global literacy rate in 1998 was 80%) or fraction or as a multiple.

What is the difference between ratio and rate?

A ratio is the comparison between two numbers with the same unit. For example 3 oranges to two oranges. On the other hand, a rate is an indication of the measurements of different units per unit. For example, the statement 3 oranges/ person shows the relationship between the measurement of oranges per person

page 60;Question#4:

4. Determine the unit rate in each situation.

a) An orca swims 110 km in 2 h.

b) A Canada goose flies 800 km in 12.5 h.

64 km/hr

c) Cathy plants 45 daffodils in 30 min.

pg61; question 10

10. Trevor rode his mountain bike 84 km in 3 h. Jillian rode 70 km in 2.5 h. Who is
the faster cyclist? How do you know? They both have the same speed.

#### 1 comment:

×Jusŧıŋ£8-17× said...

goood job , you did a good job with the colours .