Question

Tell how to find 81-16 using mental math

Answer 1

Mental math means calculating the given numbers without using anything that can help you solve the problem like paper and pen, calculator, etc.
Now let’s have 81-16
=> 81 -16
=> 65

Now, let’s check if our answer is correct by adding the answer or the difference by the subtrahend.
By the way in subtraction
81 => minuend
16 => subtrahend
65 => difference

=> 65 + 16
=> 81

Our answer is correct. Hope this help.

Answer 2

we have

$(81-16)$

One way to use mental math is to add $4$ to both $81$ and $16$

so

$81+4=85\\ 16+4=20\\ 85-20=65$

therefore

$81-16=65$

the answer is

$65$