N6: DETERMINE AN APPROXIMATE SQUARE ROOT

OF POSITIVE RATIONAL NUMBERS THAT ARE NON

PERFECT SQUARES

Grade 9

IdentifyComplete that table with perfect squares and non perfect squares that are quite close in value.

Perfect Squares Non-perfect squares

EstimateWithout a calculator, estimate the value of the square roots. Use the “bigger than, smaller than” rule.

Example:

bigger than smaller than

that means

40

4.640

636 749

30 22 10

34 29 56

75 7 60

A LITTLE GAME…I NEED 3 VOLUNTEERS…

GOAL: MAKE A NUMBER LINE SHOWING THE APPROXIMATE SQUARE ROOT OF A

NON PERFECT SQUARE EX.√50

Non perfect squares in the form of decimals:

√o.79 ≈ √? = 0. so our answer will be a little bit

√o.86 ≈ √? = 0. so our answer will be a little bit

√1.42 ≈ √? = 0. so our answer will be a little bit

Which is better?

How can we determine which answer is closest?

(At least two methods)

4.420

3.529

6.875

6.27

5.760

5.420

4.529

7.875

7.27

6.760

Non perfect squares in the form of fraction:

≈ √? = 0. so our answer will be a little bit

≈ √? = 0. so our answer will be a little bit

≈ √? = 0. so our answer will be a little bit

15

8

17

10

99

25

“approximately” can be expressed 3 different ways

≈

Explain the answer to the following (WITHOUT using a calculator)

27

10

Why may this be approximate?

Give the answer to the following (USING a calculator)

60

15

Whole number: Fraction:

Decimal:

Give me a number that has a square root between 7 and 8.

Tip: find the square roots first and then place them on the number line.

Click icon to add picturePlace the following on a number line:

√8

√2

√6

√25/4

√6.25

If a circle has an area of 50 cm², what is its radius?

Ar

Estimate the square root. EXPLAIN YOUR STRATEGY .

√300=

√0.45=

√(24/65)

√1.4

Verify your answers with your calculator.

In finding the √87 using the √ button on his calculator, Ryan said the exact answer is 9.327379053.

Is this exact? Why or why not?

Identify a whole number with a square root between six and seven.

Identify a rational number with a square root between seven and eight.

Home work!!!

Let’s practice what we learned to reinforce all these new and exciting concepts!

P.12 #13a, # 14 (remember that perimeter is the distance around an object),15,16,18

P. 18#5,6,811,12

In class assignment to hand in: p.21 #1-8, 10-11

40 points!

Describe

What shape does the package for a Toblerone bar look like? Draw a picture to show the shape. Estimate the size of the bar and package. Then estimate how much cardboard it would take to make the package.

Image reproduced from http://www.chocablog.com/wp-content/uploads/2006/07/toblerone2.jpg

ExplainLook at the object on the right. Is it a regular shape, or is it made of up smaller shapes? Explain your answer, using a diagram if possible.

Image reproduced fromhttp://admin.amccinc.com/Uploads/P1010001.JPG

ExplainThe diagram on the right is a composite shape. What basic shapes is it made from? What object might this diagram represent?

CalculateWhat is the surface area of the diagram on the right? Draw the different surfaces, and calculate the total surface area.