Probability

Everything you need to know is here:

http://www.mathsisfun.com/data/probability.html

There are some questions at the bottom of the page. Do try them. They are more difficult than you will need for Level 2
There is also a link to activities involving rolling dice. Do try these activities if you have time. 

Finding fractions of a number

For both levels 1 and 2, all you'll have to do with fractions is find fractions of a number.

For example, you may be asked to find 1/4 of something.

To do this, simply divide by 4.

Or you might be asked to find 2/5 of something.

To do this, divide by 5 then times by 2.

In short:

To find a fraction of a number, divide by the bottom number and multiply by the top number.

And that's it!

To practise this skill, go to:

Fraction of a number

To help to visualise fractions, use this:
Match fractions to pizza

Ratio

This link is very good... (but don't worry too much about  Page 2)

Percentages

How to find a percentage of something.

There are three easy ways.

1. Multiply by the percentage and divide by 100.

eg. 67% of 250 = 67 x 250 ÷ 100 = 167.5


2. Turn the percentage into a decimal and multiply.

eg. 67% of 250 = 0.67 x 250 = 167.5


3. Convert percentage into fraction and find the fraction

25% of something is a quarter of something (ie. divide by 4)

Other percentages - fractions:
20% is 1/5
10% is 1/10
5% is 1/20

(The first two methods will always work and are very easy to do if you have a calculator. The third method is good if you want to do something quickly without a calculator and it is a percentage that easily turns into a fraction)


If you're feeling confident with the third method, you could try and combine different fractions to make percentages.

eg. 75% = 50% + 25% = 1/2 + 1/4 !


Here is a simple quiz to test your ability to find percentages of numbers. You will need a calculator.

Distance / Speed / Time

Cover one up, and what remains will give you the answer.

ie. D = S x T
S = D/T
T= D/S

Decimals

(By which we mean "decimal fractions")



Here are some resources that will help your understanding of how decimal fraction work and how they relate to other fractions:

Here is a brilliant tool for comparing decimals - take two decimal fractions (eg. 0.91 and 0.835) and see how they are built of tenths, hundredths and thousandths.

This is the decifractator - it's a very simple tool that converts fractions into decimal fractions.

Average

This video explains why we have different types of average (mean, median and mode) and how they are worked out.




Here is a good activity to check you understand mean, median, mode and range.