1718 WB1Y CH10 Lesson 4

• Wiskunde
• Middelbare school
• vwo
• Leerjaar 1

Which exercises/theory should I discuss on the board?

Using the calculator

Your calculator follows the order of operations
(calculation order):
1. Brackets
2. Powers
3. Multiply and Divide from left to right
4. Add and Subtract from left to right

Fractions

To type a fraction you can use the division
button.

Calculations with fractions

When doing calculations with fractions on your
calculator, remember the order of operations.
Use brackets if needed.

Calculate

2​6​​5​​⋅18=

Fractions <--> Decimal numbers

You can use this button to switch your display
between fractions and decimal numbers.

Rounding off decimal numbers

Some fractions have an infinite number of decimals.
If you type in                                   your screen will give:
2.4285714286

There should be more numbers after the decimal point, but there is not enough room on your calculator to show them all.

Rounding off decimal numbers

                                   
The decimal number can be rounded off.
When rounding off to 1 decimal place, look at the 2nd decimal, if the 2nd decimal is a 0/1/2/3/4, leave the 1st decimal as it is. if the 2nd decimal is a 5/6/7/8/9, increase the 1st decimal by 1. (When rounding to 2 decimal places, look at the 3rd decimal, etc)
To one decimal place: 2.4               (because the 2nd decimal is a 2)
To two decimal places: 2.43          (because the 3rd decimal is an 8)
To three decimal places: 2.429     (because the 4th decimal is a 5)

What is 2.4285714286 rounded off
to 4 decimal places?

Approximately sign

When rounding off a decimal number you use the           -sign.
This sign means "is approximately equal to".

If a number is not rounded off, you use the        -sign.
This sign means "is (exactly) equal to".

Homework Tuesday

Make and correct from §10.4: 19 - 28

Make and correct any exercises from Refresh, §10.2 and §10.3 you have not done yet (see studyplanner).