Hi,

As it often happens, I believe it is a mix of the two ;p

You always have to provide the right calculation, because if you do it wrong, they'll ask questions like "are you sure?" and you would need to compute the math once more.

I confess that it is expected that you are able to do a few maths in your head and maybe it would be better for you to exercise a bit your math abilities, before the interview.

E.g., it is generally expected that you are able to do 27/5 in your head pretty quickly (obtaining a result of "around 5,4"), while it is acceptable if you do your calculations on a paper if you are asked to do 1.547/32*4 ;p

Also, during interviews, it is acceptable to make a few rounding and I strongly encourage you to do it. E.g., 5,4 -> 5,5, 90 -> 100, and so on. Always share your thought with the interviewer, to check with them if it is acceptable for you to do such a rounding.

If your interview is tomorrow, I would go for the right results in more time than wrong results in a short time, of course.

Regarding your last question, it is always better for you to share as much of your math with the interviewer so that he/she can correct you if you are making mistakes and can follow your line of thoughts (the numbers don't have to seem popped out of your head ;p).

Thus, I would say "I'm going to divide the number of houses for the number of people, to obtain the number of houses per person. Thus, I would divide 27 million houses for 5 million people, obtaining around 5,4 houses per person, that I would like to round up at 5,5 for easiness of calculation"

Hope you'll find it useful!

Hi,

As it often happens, I believe it is a mix of the two ;p

You always have to provide the right calculation, because if you do it wrong, they'll ask questions like "are you sure?" and you would need to compute the math once more.

I confess that it is expected that you are able to do a few maths in your head and maybe it would be better for you to exercise a bit your math abilities, before the interview.

E.g., it is generally expected that you are able to do 27/5 in your head pretty quickly (obtaining a result of "around 5,4"), while it is acceptable if you do your calculations on a paper if you are asked to do 1.547/32*4 ;p

Also, during interviews, it is acceptable to make a few rounding and I strongly encourage you to do it. E.g., 5,4 -> 5,5, 90 -> 100, and so on. Always share your thought with the interviewer, to check with them if it is acceptable for you to do such a rounding.

If your interview is tomorrow, I would go for the right results in more time than wrong results in a short time, of course.

Regarding your last question, it is always better for you to share as much of your math with the interviewer so that he/she can correct you if you are making mistakes and can follow your line of thoughts (the numbers don't have to seem popped out of your head ;p).

Thus, I would say "I'm going to divide the number of houses for the number of people, to obtain the number of houses per person. Thus, I would divide 27 million houses for 5 million people, obtaining around 5,4 houses per person, that I would like to round up at 5,5 for easiness of calculation"

Hope you'll find it useful!