# 1718 WA2X §3.2

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1 / 15
Slide 1: Tekstslide
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In deze les zitten 15 slides, met interactieve quizzen en tekstslides.

Lesduur is: 50 min

## Onderdelen in deze les

Study planner from mr van der Heijden

#### Slide 1 -Tekstslide

Which exercises from the homework should I discuss on the board?

(Type the exercise number (eg. 5 or 7f), if you want more then one exercise, type a separate answer for each exercise, if you understood everything type "nothing")

#### Slide 2 -Woordweb

§3.2 Square roots
What is a square root?
Finding the square root is the inverse of squaring
(In the same way that dividing is the inverse of multiplying and  subtracting is the inverse of adding)

#### Slide 3 -Tekstslide

§3.2 Square roots
Why is it called the square root?
In year 3 you will learn about the cube root, fourth root, fifth root, etc. They are the inverse of raising a number to the third power, fourth power, fifth power, etc.

#### Slide 4 -Tekstslide

§3.2 Square roots
Notation
Sometimes the square root is written as           , but           is more common.
Anything that is written under the "tail" of the square root sign should be treated as if it is written between brackets, so should be calculated before you find the square root.

#### Slide 5 -Tekstslide

§3.2 Square roots
Order of operations
1. Calculate what is between brackets
2. Raising to a power and finding roots
3. Multiply and divide from left to right
4. Add and subtract from left to right

#### Slide 6 -Tekstslide

Find the square root of 25
25=

#### Slide 7 -Open vraag

Find the square root of 81
81=

#### Slide 8 -Open vraag

Find the square root of (40+60)

40+60=

#### Slide 9 -Open vraag

§3.2 Square roots
Fractions and decimal numbers
You can also find the square root of fractions and decimal numbers

#### Slide 10 -Tekstslide

Find the square root of (9/100)

1009=
A
1004.5
B
509
C
103
D
209

#### Slide 11 -Quizvraag

§3.2 Square roots
If you calculate some square roots, you get a whole number, a fraction or a finite decimal number:

If you calculate some square roots, you get a number with infinite decimals, that cannot be written as a fraction:
In this case, we say that        is an exact number, and we say 2.24 is an approximation accurate to two decimal places (2.236 is an approximation accurate to three decimal places, etc).

#### Slide 12 -Tekstslide

Between which two whole numbers does the square root of 30 lie?
A
14 and 15
B
15 and 16
C
4 and 5
D
5 and 6

#### Slide 13 -Quizvraag

Give an approximation of the square root of 13, accurate to two decimal places.
13

Homework