Percentage = (Part ÷ Whole) × 100
To find what percent one number is of another, divide the first number by the second number and multiply by 100
To find a percentage of a number, convert the percentage to a decimal and multiply by the number
To find the whole when you know the part and percentage, use Whole = Part ÷ (Percentage ÷ 100)
To find the part when you know the whole and percentage, use Part = Whole × (Percentage ÷ 100)
To find percentage increase, use ((New − Old) ÷ Old) × 100
To find percentage decrease, use ((Old − New) ÷ Old) × 100