How do you convert between fractions, decimals, and percentages?
Fraction → decimal: divide numerator by denominator
Decimal → percentage: ×100
Percentage → decimal: ÷100
Fraction → percentage: convert to decimal then ×100
How do you order mixed FDP values?
Convert all to the same form (usually decimals), then compare.
How do you find a percentage of a number?
Convert the % to a decimal and multiply.
How do you calculate percentage increase/decrease?
Change = new - original
%change = new/orginal x100
What is the key rule for solving equations?
Whatever you do to one side, do to BOTH sides.
How do you show inequalities on a number line?
Open circle = < or >
Closed circle = ≤ or ≥
Shade the direction of the solution.
How do you find the rule for a sequence?
Look at the pattern or diagram.
Identify how many items increase per step (term-to-term).
Write the nth term: (increase × n) + starting adjustment.
How do you add/subtract fractions?
Use a common denominator, then add/subtract numerators.
How do you multiply fractions?
Multiply numerator × numerator and denominator × denominator
How do you divide fractions?
Flip the second fraction and multiply (KCF: keep–change–flip).
Formula for sum of interior angles of a polygon?
(n−2)×180∘
One interior angle of a regular polygon?
(n−2)×180∘/ n
Exterior angle of regular polygon?
360 / n
What’s the method for compound shapes?
Split into rectangles/triangles → find each area → add together.
What does a scatter graph show?
A relationship between two variables.
Types of correlation?
Positive
Negative
No correlation
What is a line of best fit?
A line showing the trend used for estimating.
How do you simplify expressions?
Collect like terms (same variable and power).
How do you substitute?
Replace the variable with the given number and calculate carefully.
Expand a single bracket?
Multiply the outside term by each term inside.
Factorise?
Take out the HCF and put bracket around what remains.
Expand double brackets?
Use FOIL: First, Outside, Inside, Last.
