## Learning About Rate – Calculating Distance, Time, and Rate

### Lesson Summary:

The lesson introduces the children to the formulae used to calculate distance, time and rate.  The reading is designed to be used by the children, and they should work through the three examples before attempting the activity.  The activity provides practice in using all three formulae.

### Objectives:

• The children will understand the formulae used to calculate distance, time and rate.
• The children will be able to use the formulae to do their own calculations.

Math

### Lesson Excerpt:

We use rates practically every day when talking about speed, time or money.  But what do we mean by rate?  A rate is a ratio that compares two different kinds of numbers.

For example, you might want to calculate how long it will take you to finish reading a book by working out how many pages you read per hour. This would be a rate of time.  When you go shopping, you can decide whether to buy a large packet of cereal by working out the cost per 100g.  This will give you a monetary rate.

The rate we are going to discuss today is that of distance travelled per unit of time. This is how we write the formula to solve these rate problems: rate = distance divided by time, or r = d/t.