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

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)

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

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

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

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%

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!)

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

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

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