1. Year 8 Revision
Each slide will have a different topic. There will be questions and hints to help you.

2. Fractions, Decimals & Percentages
0.5
50%
0.25
40%
0.3
30%
Hints:
Draw out the table and fill in the missing gaps (use your book if you get stuck)

3. Fractions, Decimals & Percentages
Hints:
To convert a decimal to a percentage – multiply the number by 100
To convert a percentage to a decimal – divide the number by 100
To convert a fraction to a percentage – Multiply the denominator number to make 100 and do the same to the numerator e.g. ⅘ (5 x 20 = 100) (4 x 20 = 80) = 80/100 =80%
To convert a percentage to a fraction – put it over 100 e.g. 25% = 25/100 (don’t forget to simplify)
To convert a fraction to a decimal – divide the denominator by the numerator
To convert a fraction to a decimal – put it over 100 e.g. 0.7 = 70/100 or 7/10

4. Hints:
Write BIDMAS down when you do the question so you don’t forget!

5. HCF and LCM Find the Highest Common Factor of these numbers: 18 and 30
Hints:
Write out the factors in both (in pairs)
18 = 1 & 18, 2 & 9, 3 & 6
30 = 1 & 30, 2 & 15, 3 & 10, 5 & 6
Circle the highest number that is in both
Find the Lowest Common multiple of these numbers
6 and 7
4 and 6
5 and 8
10 and 4
16 and 5
14 and 21
Hints:
Write out the timestables for both numbers
6, 12, 18, 24, 30, 36, 42
7, 14, 21, 28, 35, 42
Until you find a number that is in both

6. Percentage of an Amount
Remember the Percentage tree
20%
Two lots of 10%
Find the following:
50%
Half it
10%
Divide by 10
25%
Half it & Half it again 80
100%
75%
Add 50% & 25% 5%
Divide by 10 then half it
15%
Add 10% & 5%

8. Area & Perimeter Area = L x W
Perimeter = the distance around the outside
9cm
5cm
9cm
2cm
12cm
Hints:
Don’t forget to write your answer in units2
e.g. 24cm2
5cm
4cm
Hints: Add up all the sides (even the missing sides!)

9. ½ base x (vertical) height
Hints:
Area of a triangle =
½ base x (vertical) height
Don’t be fooled into using the diagonal height

10. Hints:
Angles in a triangle = 180°
Use your calculator
180 – The other numbers inside the triangle

11. Angles Hints: Angles on a straight line = 180°
Angles around a point (Circle) = 360°