Exam Revision YR 9 Flashcards
How do you calculate percentage change?
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.
What are the Index Rules?
Multiplying - add the powers
Dividing - Subtract the powers
Power of a power - multiply the powers
How do you convert reoccurring decimals to fractions
x=0.77
10x=7.77
9x=7
x=7/9
How do you find the equations of straight lines?
y=mx+c (find gradient then sub)
How do you find the gradient?
Change in y / change in x
How do you find perpendicular lines
-1/m
What do parallel lines have?
The same gradient.
What is a rogue value?
An anomaly
What is an isolated value?
A possible value but doesn’t fit.
What is a quadratic sequence?
A sequence with a second difference.
What are the rules for quadratic sequences?
Original term - n2 term then add on to n2 coefficient.
