Percentages of shapes
Sponsored Links
This presentation is the property of its rightful owner.
1 / 14

Percentages of shapes PowerPoint PPT Presentation


  • 127 Views
  • Uploaded on
  • Presentation posted in: General

Percentages of shapes. Estimating percentages. Estimating percentages. Equivalent fractions, decimals and percentages. Table of equivalences. Table of equivalences. Ordering on a number line. Dominoes. Calculating percentages mentally. Some percentages are easy to work out mentally:. 1%.

Download Presentation

Percentages of shapes

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Percentages of shapes


Estimating percentages


Estimating percentages


Equivalentfractions,decimalsand percentages


Table of equivalences


Table of equivalences


Ordering on a number line


Dominoes


Calculating percentages mentally

Some percentages are easy to work out mentally:

1%

Divide by 100

To find

10%

Divide by 10

To find

25%

Divide by 4

To find

50%

Divide by 2

To find


Calculating percentages mentally

20%

30%

60%

15%

75%

11%

2%

49%

150%

17.5%

0.5 %

We can use percentages that we know to find other percentages.

Suggest ways to work out:


Spider diagram


Finding the original amount

We can use a unitary method to solve these type of percentage problems. For example,

Christopher’s monthly salary after a 5% pay rise is £1312.50. What was his original salary?

The new salary represents 105% of the original salary.

105% of the original salary = £1312.50

1% of the original salary = £1312.50 ÷ 105

100% of the original salary = £1312.50 ÷ 105 × 100

= £1250

This method has more steps involved but may be easier to remember.


Finding the original amount


Finding the original amount

actual increase

Percentage increase =

× 100%

original amount

actual decrease

Percentage decrease =

× 100%

original amount

Sometimes, we are given an original value and a new value and we are asked to find the percentage increase or decrease.

We can do this using the following formulae:


  • Login