Le Matou matheux: percentages

Calculating percents (easier)

The price of an item decreases by 10%.
To calculate its new price, you have to multiply the old price by .

The price of an item increases by 10%.
To calculate its new price, you have to multiply the old price by .

The population of a city by 12%.
To calculate the city's new population, you have to multiply the old population by 1.12.

The population of a city increases by
To calculate the city's new population, you have to multiply the old population by 1.2.

The number of participants in a race decreases by 5%.
To calculate the new number of participants, you have to multiply the old number by .