Math unit1 decimals and fractions

transcript

Unit 1Decimals & Fractions

Presentation 1 Multiplying and Dividing Decimals

Presentation 2 Converting Fractions and Decimals

Presentation 3 Negative Numbers

Presentation 4 Operations with Negative Numbers

Presentation 5 Estimating Answers

Multiplying and Dividing Decimals

To multiply by 100, move the decimal point 2 places to the right, giving:

similarly

To divide by 100, move the decimal point 2 places to the left, giving:

similarly

You have finished viewing the presentation

Multiplying and Dividing Decimals

Please choose an option

Return to the Start

Unit 1Decimals & FractionsConverting Fractions and

Decimals

Fractions to Decimals

Express as a decimal.

Here it is best to divide out:

Express as a decimal.

Here it is easier to make the denominator a multiple of 10

Express as a decimal in its simplest form

Converting Fractions and Decimals

Return to the Start

Negative Numbers

Example 1

What is 15oC less than 26oC?

Solution

26oC – 15oC = 11oC

Example 2

What is 15oC less than 10oC?

Solution

10oC – 15oC = – 5oC

Negative Numbers

Return to the Start

Unit 1Decimals & FractionsOperations with Negative

Numbers

Remember …

Example 1

Remember …

Example 2

Remember …

Example 3

Remember …

Example 4

Operations with Negative Numbers

Return to the Start

Estimating Answers

It is important to be able to estimate answers to complex calculations.

Without a calculator which of the answers is equal to ?

A 1∙649 B 16∙494 C 164∙945

Without a calculator which of the answers is equal to ?

You have to approximate each answer in the calculation. Hence, for example

A 1∙649 B 16∙494 C 164∙945

Estimating Answers

Return to the Start

Math unit1 decimals and fractions

Education