C8 Ratio

C8 Ratio

Use your name, start faster

(I can address your questions during Q & A)

- Assess your level in Period 1.

- Practise more WB Qns in Period 2.

- Take photos and upload to G.C.

Announcement

• Bring your math workbook 1A (Corrections completed) - collection

• Bring your math file, math booklet on Tues, 6 Jul 2021 (collection)

• Content page will be updated on Onenote by Sat, 3 Jul 2021

• Check the content page and file (Let me know if I miss out some worksheets in the content page)

• This math file, WB, booklets will help you to tidy up and revise for EOY

Level of Learning

• Level 1: How to express quantity of the type without unit in ratio?

• Level 2: How to express ratio in the Simplest Ratio? (Equivalent ratio)

• Level 3: How to express fraction as ratio, (vice versa)?

• Level 4: How to apply ratio into real-world context?

Level 1 and 2

Level 1: How to express quantity of the type without unit in ratio?

Level 2: How to express ratio in the Simplest Ratio? (Equivalent ratio)

Did you fall into my trap?

• Did you know that 100 cm = 1 m?

• Did you change to the same unit before you compare? (Or leave it as 2.4 : 204 = 1 : 85)

• Did you take out the units before expressing as ratio? (Or leave it as 240 cm : 204 cm, 2.4 m : 2.04 m)

• Did you reduce to the simplest ratio? (Or leave it as 240 : 204)

Multiple Select

Which of these ratios are equivalent to p : q?

• p² : q²

• 6p : 6q

• 1/q : 1/p

• p + 1 : q + 1

Equivalent ratio

It means that when you reduce the ratio into simplest ratio, they will be the same.

When do you see it?

When the ratios are multiples of each other.

Level 3

How to express fraction as ratio, vice versa?

Did you fall into my trap?

• Names that you see are purely coincidental and they are not real representation in life.

• As the fraction is smaller than 1, did you know that Ammar has lesser money than Adam?

• Did you know that Ammar has 2 units while Adam has 7 units?

• Did you express the ratio in the order that the question want? (or you express the question in the way it is given)

Open Ended

WB p19 Q4.

If 2x = 3y, then x:y = 2 : 3. Do you agree? explain 

(you can draw diagram to help you to explain)

2x = 3y, then x:y = 3 : 2

Why?

Let's use an example

Example: Ruler A is 3 cm and Ruler B is 2 cm

2 sets of length of ruler A = 3 sets of length of ruler B

Ruler A is longer than Ruler B

(that's why less Ruler A is needed to match up the length of Ruler B)

Did you fall into my trap?

• Did you express as 4/5 directly without reading the question carefully?

• Did you manage to identify that there are a total of 9 units (4u + 5u = 9u) ?

Open Ended

Pause and reflect (5 min)

Review the concepts.

If you have questions, you can pose it now.

I will select the common questions and answer them

(For those questions that I couldn't answer in time, I will collate into OneNote and text the students)

Level 4

How to apply ratio into real-world context?

Did you fall into my trap?

• Did you know that 1000 mL = 1 L?

• Did you change to the same unit before you compare?

• Did you take out the units before expressing as ratio?

• Did you reduce to the simplest ratio?

Tip

1. Identify a relation between unit and the quantity given in question

2. Once you found the relation, find 1 unit.

3. Then answer to the question requirement.

Level of Learning

• Level 1: How to express quantity of the type without unit in ratio?

• Level 2: How to express ratio in the Simplest Ratio? (Equivalent ratio)

• Level 3: How to express fraction as ratio, (vice versa)?

• Level 4: How to apply ratio into real-world context?

Homework

Complete

WB p21 to 22

Q10, 11, 12, 13, 14, 15

Let's summarise what we have learnt today.