Mathematics doubts

Question

the value of 124.2+52.487 with due regard to significant places is ?

Answer 1

Suppose we took the number 124.2.   There are no other significant digits after the 2 to the right side of the decimal point.  So we see that there is an imaginary zero. 

 

We can write this as 124.200

 

Therefore, you have       124.200 + 52.487

 

Now you can add these numbers with each digit lined up by place value.

 

------------------------------------------------------------------------------------------------------------

 

Here is an example to help you understand:

 

Subtract the amount of $15.65 from a $20 bill.  The $20 can be written as $20.00, since the amount of money is written in that form.  So you would say

 

$20.00 - $15.65

Answer 2

124.2+52.487 would be considered to be

124.2+52.5 because the one DP accuracy of first number limits the answer's accuracy, thus you'll have to round the 3 DP number to 1 DP as I have shown.