Math Club – Grade 3

Class # 2 : 10/14/2014

GCF: Greatest Common FactorIt is the highest common FACTOR for 2 or more numbers

What is the GCF for 4 and 6?

What is the GCF for 6 and 12?

What is the GCF for 4 and 18?

What is the GCF for 12 and 18?

Practice 1: Greatest Common Factor

Find GCF for the following:

a. GCF (6 and 9)

b. GCF (15 , 30)

c. GCF (10 ,11)

d. GCF (14 and 21)

e. GCF (16, 24)

Practice 2: Order of Operations

a. Evaluate: 12+ 5 x 3 – 10

b. Evaluate: 14 - 2 x 4 + 4 ÷ 2 – 4

c. Evaluate: 4 x (8 - 6) ÷ 2

d. Evaluate: (3+2) x (4 – 1) ÷ 5

e. Evaluate: 5 x 4 x 5 x 4 x 5 x 5 x 4

Practice Question 3

What number does N represent in equation 6 x 7 x 40 = 5 x 8 x N

Practice Question 4

Terry has 5 stickers in a row on a piece of paper. The star is one to the left of the puppy. The rainbow is to the right of the heart. The puppy is three to the left of the kitten. Which sticker is in the middle of the row?

Practice Question 5

Jorge is the first person standing in line. His friend, Eli, is the 21st person on that same line. How many people are standing between them on line?

Practice Question 6

Grace chooses five different numbers from the list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. Two of those numbers are 4 and 5, and they are the only two numbers she picks that differ by 1. What is the greatest possible sum of the five numbers?

Practice Question 7

Find the value of 87 – 76 + 65 – 54 + 43 – 32 + 21 – 10

Practice Question 8

A 7 x 7 square is marked off into forty-nine 1 x 1 small squares. Each of the small squares along the edges of the large square is painted blue. How many small squares are painted blue?

Practice Question 9

The numbers 1, 2, 3, 4, 5 and 6 are placed in the diagram, one in each circle. The sum of the numbers along Side A is 13, along Side B is 13 and along Side C is 6. What number is in the circle at the top of the diagram?

Side C

Side A Side B

Practice Question 10

For a certain 3 digit number:• the digits are in increasing order• the difference of the greatest and least digits

is 7• it is a multiple of 9 and greater than 200Find the 3 digit number

APPENDIX

Factors

What are the factors of 4 1, 2, 4

What are the factors of 6 1, 2, 3, 6

What are the factors of 12 1, 2, 3, 4, 6, 12

What are the factors of 181, 2, 3, 6, 9, 18

Order of OperationsObserve the following priorities from left to right:

1.Do operations inside the brackets first, from left to right

2.Do Multiplication and Division next, from left to right

3.Do Addition and Subtraction , from left to right

Brackets division & multiplication addition & subtraction

Example 3 + 4 x 5 – 8 ÷ (9 – 7)= 3 + 4 x 5 – 8 ÷ 2= 3 + 20 – 4= 19

Example: Order of Operations

Evaluate: 3 x 4 – 2 x 5 + 6 ÷ (2 + 1)

3 x 4 – 2 x 5 + 6 ÷ (2 + 1) 3 x 4 – 2 x 5 + 6 ÷ 33 x 4 – 2 x 5 + 6 ÷ 3 3 x 4 – 2 x 5 + 23 x 4 – 2 x 5 + 2 12 – 10 + 212 – 10 + 2 4

Tips and TricksDivision by 2 If the last digit is divisible by 2, then the whole

number is divisible by 2

Division by 4 If the last two digits are divisible by 4, then the whole number is divisible by 4

Division by 8 If the last three digits are divisible by 8, then the whole number is divisible by 8

e.g. 536

Tips and Tricks

Division by 2If the last digit of a number is ‘even’ number,

then the number is fully divisible by 2

Quiz: Which of the following is divisible by 2456 or 442321 or 442

Tips and Tricks

Division by 4If the last 2 digit of a number are divisible by 4,

then the number is fully divisible by 4

Quiz: Which of the following is divisible by 4456 or 442336 or 444

Tips and Tricks

Division by 3

If the sum of digits of a number is divisible by 3, then the number is divisible by 3

Quiz: Which of the following is divisible by 3456 OR 334

Tips and Tricks

Division by 9

If the sum of digits of a number is divisible by 9, then the number is divisible by 9

Quiz: Which of the following is divisible by 9456 OR 334

Factors

What are the factors of 4 1, 2, 4

What are the factors of 6 1, 2, 3, 6

What are the factors of 12 1, 2, 3, 4, 6, 12

What are the factors of 181, 2, 3, 6, 9, 18

Order of OperationsObserve the following priorities from left to right:

1.Do operations inside the brackets first, from left to right

2.Do Multiplication and Division next, from left to right

3.Do Addition and Subtraction , from left to right

Brackets division & multiplication addition & subtraction

Example 3 + 4 x 5 – 8 ÷ (9 – 7)= 3 + 4 x 5 – 8 ÷ 2= 3 + 20 – 4= 19

Example: Order of Operations

Evaluate: 3 x 4 – 2 x 5 + 6 ÷ (2 + 1)

3 x 4 – 2 x 5 + 6 ÷ (2 + 1) 3 x 4 – 2 x 5 + 6 ÷ 33 x 4 – 2 x 5 + 6 ÷ 3 3 x 4 – 2 x 5 + 23 x 4 – 2 x 5 + 2 12 – 10 + 212 – 10 + 2 4

Tips and TricksDivision by 2 If the last digit is divisible by 2, then the whole

number is divisible by 2

Division by 4 If the last two digits are divisible by 4, then the whole number is divisible by 4

Division by 8 If the last three digits are divisible by 8, then the whole number is divisible by 8

e.g. 536

Tips and Tricks

Division by 2If the last digit of a number is ‘even’ number,

then the number is fully divisible by 2

Quiz: Which of the following is divisible by 2456 or 442321 or 442

Tips and Tricks

Division by 4If the last 2 digit of a number are divisible by 4,

then the number is fully divisible by 4

Quiz: Which of the following is divisible by 4456 or 442336 or 444

Tips and Tricks

Division by 3

If the sum of digits of a number is divisible by 3, then the number is divisible by 3

Quiz: Which of the following is divisible by 3456 OR 334

Tips and Tricks

Division by 9

If the sum of digits of a number is divisible by 9, then the number is divisible by 9

Quiz: Which of the following is divisible by 9456 OR 334

Factors

What are the factors of 4 1, 2, 4

What are the factors of 6 1, 2, 3, 6

What are the factors of 12 1, 2, 3, 4, 6, 12

What are the factors of 181, 2, 3, 6, 9, 18

Order of OperationsObserve the following priorities from left to right:

1.Do operations inside the brackets first, from left to right

2.Do Multiplication and Division next, from left to right

3.Do Addition and Subtraction , from left to right

Brackets division & multiplication addition & subtraction

Example 3 + 4 x 5 – 8 ÷ (9 – 7)= 3 + 4 x 5 – 8 ÷ 2= 3 + 20 – 4= 19

Example: Order of Operations

Evaluate: 3 x 4 – 2 x 5 + 6 ÷ (2 + 1)

3 x 4 – 2 x 5 + 6 ÷ (2 + 1) 3 x 4 – 2 x 5 + 6 ÷ 33 x 4 – 2 x 5 + 6 ÷ 3 3 x 4 – 2 x 5 + 23 x 4 – 2 x 5 + 2 12 – 10 + 212 – 10 + 2 4

Tips and TricksDivision by 2 If the last digit is divisible by 2, then the whole

number is divisible by 2

Division by 4 If the last two digits are divisible by 4, then the whole number is divisible by 4

Division by 8 If the last three digits are divisible by 8, then the whole number is divisible by 8

e.g. 536

Tips and Tricks

Division by 2If the last digit of a number is ‘even’ number,

then the number is fully divisible by 2

Quiz: Which of the following is divisible by 2456 or 442321 or 442

Tips and Tricks

Division by 4If the last 2 digit of a number are divisible by 4,

then the number is fully divisible by 4

Quiz: Which of the following is divisible by 4456 or 442336 or 444

Tips and Tricks

Division by 3

If the sum of digits of a number is divisible by 3, then the number is divisible by 3

Quiz: Which of the following is divisible by 3456 OR 334

Tips and Tricks

Division by 9

If the sum of digits of a number is divisible by 9, then the number is divisible by 9

Quiz: Which of the following is divisible by 9456 OR 334

AnswersQuestion # Answer

1 (a) 3; (b) 15; (c) 1; (d) 7; (e) 8

2 (a) 17; (b) 4; (c) 4; (d) 3; (e) 40,000

3 N = 42

4 Heart

5 19

6 29

7 44

8 24

9 6

10 279