Question

How do you use mental math to find the product of “64” and “25”?

Answer 1

Hint: In mental math’s the calculations are created in a easy way by producing zeroes in the question, that is numbers given are broken in the way in which the next number obtained should contain at least one zero, if the previous number does not have, and accordingly number of zeroes are increased if already present then.

Complete step-by-step answer:
Here we are going to use the distributive property of the mental maths that is:
 \[ \Rightarrow \left( {a + b} \right)c = a \times c + b \times c\]
Now breaking the terms of the given question according to the property of the mental maths we obtain:
 \[ \Rightarrow 64 = \left( {60 + 4} \right)\]
Here we are not breaking “25” because every even multiple of “5” gives a zero in the result and here we have an even number in the next term.
Now on multiplying both the term we get:
 \[ \Rightarrow \left( {60 + 4} \right) \times 25 = 60 \times 25 + 4 \times 25 = 1500 + 100 = 2500\]
This is our required answer.
So, the correct answer is “2500”.

Note: Mental math is used to simplify the calculation because having zeroes in the numbers which are going to be multiplied are very easy to solve as earlier when the numbers are not broken accordingly. Even larger numbers can be multiplied without using a calculator, so mantle math is a lengthy process but it makes your calculation very easy.