Maths Presentation

By: Johanes and Gopas

RATIO

Ratio is the comparison between 2 or more

things. It can be expressed as a fraction, using this (:), and using the word or.

What is Ratio?

In this topic we learn ratio. In ratio there are comparisons between objects. In here, we learn how to order, simplify, and convert.

Simplify: to simplify we need to divide two or more things (a and b) with the same amount.

Convert: In ratio sometimes we have different quantities. But in ratio we need to make the two or more in the same quantity.

Order: In ratio we need to compare two or more objects. But we need to order them based on the question. Because of that we need to be accurate at the question.

Concept

1. Liam says that he has four times as much money as

BronwynA. What is the ratio of:

i. Liam’s amount of money to Bronwyn’s amount of money

ii. ii. Bronwyn’s amount of money to Liam’s amount of money

B. Do we know the amount of money that Liam or Bronwyn actually has?

Exercise

a. i) 4 : 1 ii) 1 : 4 No, because we only know the ratio

Answer

Exercise

a. Concrete : 1 + 2 + 4 = 7 cement : 1 Fraction : =

Answer

Equivalent Ratio

Equivalent ratio is 2 different ratio with different

number that have the same amount. It is formed by multiplication and division.

What is equivalent ratio?

From the previous definitions, equivalent ratio

found when a ratio is multiplied or been divided.

To know the same amount we need to multiply or divide with the same amount.

Concept

1. N) 24 : 36 = : 3

Exercise

24 : 36 = 2 : 3 why? 36 12 So, 24 12 = 2

Answer

5) In 7M there are 16 boys and 14 girls. What

is the ratio of a) boys to girls

Exercise

Ratio: boys to girls = 16 : 14

Answer

Direct Proportion

Direct Proportion is when 1 amount increases

another amount increases at the same rate.

What is direct proportion

In this unit we also learn about direct

proportion. As it mentioned in the definition, direct proportio is when 1 amount increase and another amount increase with the same rate.

To find direct proportion you need to: you need to multiply the amount with the same rate from the information given.

Concepts

You are paid $20 per hour -How much will you get if you work 7 hours?

Example

1 hour = $20 7 hour= $140

Earnings X worked hours

Answer

Indirect Proportion

Indirect proportion is when 1 amount

decrease and the other amount increase with the same rate.

What is inderect proportion?

In inderect proportion, as mentioned in the

definition, inderect proportion is when 1 amount decrease and the other decrease with the same amount.

So you need to add and subtract with the same rate or amount.

Concepts

The further away you from the light, less

bright it is

Example

Scale

Scale is the ratio betwee the replica and the

real object.

What is scale?

To find scale, we need to divide the real object

measurements with the replica measurements.

Concept

What is the scale between the replica and the

real object if the replica is 10 m and the real object is 20m?

Example

20 So it become 1 : 2LOLOLOLOLOLOLOLOOLOLOLOLOLOLOLOLO

Answer