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SAI INTERNATIONAL SCHOOL

Subject – Mathematics

Chapter – MONEY

Sub-topic-9:- UNIT AND MULTIPLE COST&BILL-

Unit cost – Cost of one.

Multiple Cost – Cost of many.

Unitary Method-This is a method for solving a problem by first finding the value of a
single unit and then finding the necessary value by multiplying the single unit value.

The unitary method is also known as the method of ones.

To get more value we will multiply.

To get less value we will divide.

Rule-1: If the cost of one item is given and we have to find out the cost of any number
similar items ,then we will multiply the cost with the given number of items.

Example-1: The cost of one mobile is ₹30,000.What will be the cost of 12 such mobiles?

Solution- Cost of a mobile = ₹30,000

Cost of 12 mobiles= ₹30,000x12=₹3,60,000

Hence, cost of 12 such mobiles is ₹3,60,000.

Rule-2: If the cost of many items of similar kind is given and we have to find out the
cost of one item, then we will divide the total cost by the given number of items.

Example-2: 8 fans cost ₹7648.What is the cost of 1 fan?

Solution- Cost of 8 fans = ₹7648

Cost of 1 fan= ₹7648÷8=₹956

Hence, cost of 1 fan is ₹956.

Rule-3: When the cost of a certain number of items of the same type is given and we
have to calculate the cost of another number of those items ,we first determine the cost
of one item and then multiply the result by the required number of items.