3rd Class Mathematics Division Division

LEARNING OBJECTIVES

This lesson will help you to:

• recognize division as equal sharing.
• understand the concept of division as equal grouping.
• prepare division facts by using multiplication tables.

Real life Examples

• When you are a eating a birthday cake, you have to make equal shares of the cake, so that everyone gets their share. For this you divide the cake in equal sizes.
• If you have Rs. 20 and you want to buy chocolates and each chocolate is of Rs. 5. By using the method of division you can find out the number of chocolates you can buy. Since, 20 ÷ 5 = 4 so you can buy 4 chocolates.

DIAGRAMS/PICTURES

There are 12 daisies. Make groups of 3.

I How many groups do you get?

How many 3's are in 12?

The answer is 4. So. 12 - 3 = 4.

The symbol'\[\div \]' indicates Division.

Think: If you DIVIDE 10 into groups of two, how many groups are there?

How many groups of two are there in 10? How many two’s are there in 10?

Since 2+2+2+2+2= 10, there are FIVE twos in 10; 10 \[\div \] 2 = 5

Division is the equal distribution of a given quantity. The number to be divided is called the dividend. The number which divides is called the divisor. The answer is called the quotient. The number left after the division is called the remainder.

Chunmun bought 15 apples from fruit market. She placed 15 apples equally in 3 baskets.

Divide 15 into equal groups.

There are 5 apples in each group.

Therefore, 15 - 3 = 5

1. Mrs. Khanna got 35 flowers on her wedding anniversary.

She placed them equally in 5 vases.

There were 7 flowers in each vase.

So, 35 - 5 = 7 or

"Thirty five divided by five is seven."

2. Minki arranged 32 glasses on the dining table for guests.

Amazing Facts

• If you make groups of 1 then the answer is number itself because any number divided by 1 is the number itself. For example, 4 ÷ 1 = 4, 12 ÷ 1 =12, etc.
• If the given number ends with 0 or 5 then you can divide the number in groups of 5. For example, 15 = 3 groups of 5 or 15 ÷ 5 = 3, 10 = 2 groups of 5 or 10 ÷ 5 = 2, etc.
• If the given number ends with 0 then you can divide the number in groups of 10. For example 20 = 2 groups of 10 or 20 ÷ 10 = 2, etc.
• When any number is divided by zero, the answer is infinity.

1857 ÷ 0 = infinity.

Historical Preview

• The division symbol ‘÷’ is called ‘Obelus’ It was used in 1659 for the first time in an algebra book.

Shortcut to Problem Solving 

• To divide any number by 5, multiply by 2 and divide by 10
• To divide any number by 25 multiply by four and divide by 100.

Minki's mother made 8 groups of the glasses.

There ore 4 glasses in each group.

So, 32 - 8 = 4 or

"Thirty two divided by eight is four."

DIVISION AS REDPEATED SUBTRACTION

We know that 4 + 4 + 4 = 12 is repeated addition similarly. 12 - 4 - 4 - 4 = 0 is a repeated subtraction.

RELATION BETWEEN MULTIPLICATION AND DIVISION

20 x 30 = 600 is a multiplication fact.

The division fact for this can be written as:

                600\[\div \]30 = 20

Therefore, the multiplication is an inverse of division.

Division by Grouping/Sharing

Step 1: Take the given number of objects

Step 2: Make equal groups of the objects

Step 3: Count Number of objects in each group

Step 4: The number of objects in each group is the answer