What is X% of Y?
e.g. What is 20% of 150?
X% × Y = ?
What is
% of
?
Answer
X is what % of Y?
e.g. 30 is what % of 150?
X ÷ Y × 100 = ?%
is what % of
?
Answer
Percentage change
e.g. From 80 to 100 is what % increase?
(New − Old) ÷ Old × 100
From
to
Change
Add a percentage
e.g. 200 + 15% = ?
Number × (1 + %/100)
+
%
Result
Subtract a percentage
e.g. 200 − 15% = ?
Number × (1 − %/100)
−
%
Result
Percentage of total
e.g. 45 out of 200 students passed
Part ÷ Total × 100
out of
Percentage