4th Class Mathematics Unitary Method Introduction

     Introduction

Unitary method is a method under which a Arithmetic operations are carried out to find the value of number of items by first finding the value of one item.

Through daily life experience we know that when we increase the quantity of articles, their value increases and when we decrease the quantity of articles, their value decreases in other word more articles have more values and less articles have less values.

Let cost of 5 pencil is Rs. 10, if we increase the number of pencils their cost is increase and if we decrease the number of pencils, their cost is decrease. Like if we buy 6 pencils we have to pay Rs. 12 and if we buy 4 pencils we have to pay Rs. 8.  

In unitary method:

To get more value we multiply.

To get less value we divide.  

If price of one cycle is Rs. 1200, find the price of 5 cycles.

Solution:

Here price of 1 cycle is given and we have to find the price of 5 cycles. Therefore, we multiply the price of 1 cycle by 5. Thus, price of 5 cycles = Rs. \[1200\times 5=\] RS. 6000.  

If price of 8 bicycles is Rs. 10200, find the price of 1 cycle.

Solution:

Here price of 8 cycles is given and we have to find the price of 1 cycle. Therefore, we divide the price of 8 cycles by 8. Thus, price of 1 cycles

= Rs.\[\frac{10200}{8}\] Rs. 1275.  

To solve the problems by unitary method we follow two steps:

Step 1:   Value of unit is found.

Step 2:   Then value of the required unit is found.  

If 5 trucks can carry 1740 bags of cement. How many bags can be carried by 20 trucks?

Solution:

Step 1: To find number of cement bags which can be carried by one truck, we have to divide the total number of cement bags by the total number of trucks. Thus, number of cement bags which 1 truck can carry \[=\frac{1740}{5}=348\] Thus 1 truck can carry 348 cement bags.

Step 2: Now number of cement bags which can be carried by 20 trucks To find this, we have to multiply number of cement bags which can be carried by 1 truck by the required number of trucks. Thus number of cements bags which can be carried by 20 trucks \[348\times 20=6960\] . Thus 20 trucks can carry 6960 cement bags.