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

+ open your Notebook 

+ first the THEORY and an EXAMPLE follow!

+ after this you will make an exercise yourself

Task 1:   Find the Scale!

Posters are made for the schoolparty.

A beetle (kever) is drawn by you.

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

Make this task in your NOTEBOOK:

MAKE A RATIO TABLE in your NOTEBOOK now and fill it in!

FINALLY WRITE DOWN THE SCALE for the Beetle!

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

Solution (2):

Conclusion from this TABLE:

the ratio is  200 : 1

(and NOT 1 : 200, because the REAL OBJECT is SMALLER than 

the PICTURE)

Solution Scale task (1):

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 

Next slide shows HOW TO MAKE THE RATIO TABLE, that I asked you to make!          

FOTOVRAAG :  

COPY and FILL IN this RATIO TABLE:

FOTOVRAAG :  

Make and FILL IN a RATIO TABLE for:

Solution Task 2:

Task 3:

Make a Ratio Table in your Notebook.

Solve the question.

Task 3:

Key in your answer in the next slide.

By the way, you may also 

work with 10 percent instead of 

1 percent.

.. girls

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.

Preparing for tomorrows test:

- Make the exercises from Chapter 5 that you did not do yet!

- Make the exercises that you had wrong the first time, again.

- Do some NEW EXERCISES:

   p.190/191 Mixed exercises. Choose some of them:

   Make them in your Notebook and check them with the Solutionsbook!