Percentages Explained Simply
The word percent comes from the Latin per centum, meaning “out of a hundred”. So one percent is simply one hundredth - just like in the grid below, where each small square is one hundredth of the whole square.
25 out of 100 little squares are colored orange - that is 25%.
đź’¬ Mia asks Grandpa Theo
A jacket costs $80 and has “25% off”. How much do I actually save?
You calculate 80 × 25 ÷ 100 = 20. So you save $20 - the jacket ends up costing you only $60.
What if it were 50% off?
50% is simply half! Just divide by 2: 80 ÷ 2 = $40 savings. These shortcuts are worth remembering.
Are there more tricks like that?
Sure: 10% just means dividing by 10, 1% by 100. And 15% is just 10% plus half of 10% (which is 5%) - that way you can work out almost any percentage in your head.
A phone costs $250, and you get 12% off. How much do you save?
Answer: 250 × 12 ÷ 100 = $30
Percentages are also used for interest: if a bank pays 3% interest per year, you get exactly $30 in interest on $1000.
← Back to overview