NCERT 5th Class (CBSE) Mathematics: Order Of Operations

WHO IS RIGHT?

Meera:  3+4×8 = 56

Manu: 3+4×8 = 35

Meera and Manu were both given the same question to solve. Notice that they both got different answer because Meera added first and Manu multiplied first.

To be sure that there should be only one answer for sums like these, rules have been made for the order of operations.

A. When you have an expression with different operations follow this order:

Division → Multiplication → Addition → Subtraction

You can remember this order as DMAS.

Following the rules, Manu is right because multiplication is done before addition.

3+4×8     First multiply 4 by 8

3+32 = 35   Then add 3

3+4×8 = 35

Let us look at some more examples.

(a) 53-18÷2×5

= 53-18÷2×5       first divide

= 53-9×5            next, multiply

=53-45 = 8        finally, subtract

53-18÷2×5 = 8

(b) 7.5+7.2÷3×0.2

=  7.5+7.2÷3×0.2         first divide

= 7.5+2.4×0.2              then, multiply

= 7.5+0.48 = 7.98        finally add

7.5+7.2÷3×0.2 = 7.98