1Th/vwo Ch5 totally!/SUMMARY

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 1

Ch 5 Ratio - more practice

Rounding off this Chapter, you'll get some tasks,

to show what you've learned by now.

A little explanation, before and after the task, is also given,

to refresh your memory.

Get organised first...

Take before you:

+ pencil, pen and eraser

+ your Notebook 

Task 1:   Scale task.

Posters are made for the schoolparty.

A beetle (kever) is drawn by you.

The picture is 110 cm long. The beetle is 0.55 cm long.

Key in the right scale in the next slide.

1. 1 : 200
2. 200 : 1
3. 1 : 20
4. 20 : 1

Solution Scale task:

The picture is 110 cm long. The beetle is 0.55 cm long. The key question is:

.... cm in the drawing is  ... cm in reality

Let's calculate how many times 0.55 cm fits in 110 cm.

110 : 0.55 = 11000 : 55  

As 55 fits two times  in 110, it fits two hundred times in 11000

So, the scale is         200 : 1           

Task 2: 

Send in a pic of your calculation (the ratio table!).

Key in the discount (reduction).

Solution Task 2:

Task 3:

Key in your answer in the next slide.

By the way, you may also 

work with 10 percent instead of 

1 percent.

Solution:

Number of pupils   30    3    24

percentage              100   10    80

So because the girls are 80 percent, there are 24 girls.

How good is your understanding about ratio tables now?
On a scale of 1 to 10.

Homework time