lesson 2: squares and square roots

Learning Outcome: Learn to find the squares and square roots of whole numbers.

LESSON 2: SQUARES AND SQUARE ROOTS

Recall: A factor is a number that divides evenly into another number.Ex. the factors of 8 are 1, 2, 4, and 8

Whole numbers that only have two factors are called prime numbers. Examples of prime numbers are: 1, 3, 7, 11, 13, 17 ….

1. Divide the number (Dividend). If both divisor and quotient are equal you have a square number.

25 ÷ 5 = 5   

If Divisor = Quotient, then we have a square number.

How do we find out if a number is a square number?

Factor out all the factors of a number, if there is a odd number of factors, the number is a square number.

25: 1, 5, 25 (a factor that occurs twice is only written once)

2. Use factoring.

5 x 5 = 25 If we diagram all possible rectangles, one will have side lengths of equal units.

The square has side lengths of 5 by 5

We say that 5 is the square root of 25.

We can write this √ 25 = 5

The symbol √ = square root

When we multiply a number by itself, we have a square number.

4 x 4 = 16 3 x 3 = 9 4² = 16 3² = 9

3. Multiply a Number by Itself

a) 5 b) 9c) 16

Find the square of:

The factors of 136 are listed in ascending order:

136: 1, 2, 4, 8, 17, 34, 68, 136

Is 136 a square number? How do you know?

HINT: Think about the investigate activity we did in class

Try This:

A square number has an odd number of factors. This number has 8 factors. Not a square number.

Solution:

Follow through the examples for more instruction on finding squares and square roots

Once you feel you understand the concepts in the lesson move on to Practice Assignment

Connect/Examples – Text pg. 12-14