Уроки математики и физики (RU + UA)

четверг, 5 января 2017 г.

Lesson 1. Ratio


We use ratio to compare parts of a whole.

It this diagram, there are 6 black squares and 2 white squares.
We say the ratio of black squares to white squares is 6 to 2.
This is written as 6:2.
Both numbers in the ratio 6:2 can be divided by 2 so we can reduce the ratio 6:2 to its simplest from of 3:1.

EXAMPLE:

In a class of 24 children, 14 are girls. Find the ratio of boys to girls. Give the answer in its simplest form.
There are 10 boys. Ratio of boys to girls = 10:14. (10 and 14 can both be divided by 2).
Ratio of boys to girls = 5:7.

EXAMPLE:

Are the ratios 15:25:30 the same as 3:5:6?
15, 25 and 30 can all be divided by 5.
15 ÷ 5 = 3
25 ÷ 5 = 5
30 ÷ 5 = 6
So 15:25:30 = 3:5:6. 

Tasks to the lesson 1

Other lessons:

Комментариев нет:

Отправить комментарий