Exam Revision YR 9

Question 1

How do you calculate percentage change?

Answer 1

Calculate the difference between the two numbers being compared:
Difference = New Number - Original Number

Divide the difference by the original number and multiply the result by 100:
Percentage Change = Difference ÷ Original Number × 100
If the final answer is a negative number it is a percentage decrease, otherwise, it is a percentage increase.

Question 2

What are the Index Rules?

Answer 2

Multiplying - add the powers
Dividing - Subtract the powers
Power of a power - multiply the powers

Question 3

How do you convert reoccurring decimals to fractions

Answer 3

x=0.77
10x=7.77
9x=7
x=7/9

Question 4

How do you find the equations of straight lines?

Answer 4

y=mx+c (find gradient then sub)

Question 5

How do you find the gradient?

Answer 5

Change in y / change in x

Question 6

How do you find perpendicular lines

Answer 6

-1/m

Question 7

What do parallel lines have?

Answer 7

The same gradient.

Question 8

What is a rogue value?

Answer 8

An anomaly

Question 9

What is an isolated value?

Answer 9

A possible value but doesn’t fit.

Question 10

What is a quadratic sequence?

Answer 10

A sequence with a second difference.

Question 11

What are the rules for quadratic sequences?

Answer 11

Original term - n2 term then add on to n2 coefficient.