# Thread: Formula needed for computation

1. ## Formula needed for computation

Hi there,

I'm hoping that this is the proper place for this post, and if not, please accept my apologies up front. Really, I'm so bad at math that I'm not even sure that what I want to do is possible... so here goes...

I am in need of a formula that would calculate the following scenario: I have a contest whereby contestants can earn additional points by rating other contestants. These reward points would be awarded for every 10 votes (clarification, a vote is a rating), but for every hundred votes the amount that is awarded increases by .5, so you have something that looks like this:
001-100 = 1.0
101-200 = 1.5
201-300 = 2.0
301-400 = 2.5
...
Thus, 125 votes is worth 13 points ((100 / 10 * 1) + (20 / 10 * 1.5), 284 votes would be worth 41 points. So I am trying to find a formula that I could simply plug in the number of votes and it would return the contestant's score. Any help would be sincerely appreciated.

TIA.

2. ## Computation Formula

Hello MathDeficient
Originally Posted by MathDeficient
Hi there,

I'm hoping that this is the proper place for this post, and if not, please accept my apologies up front. Really, I'm so bad at math that I'm not even sure that what I want to do is possible... so here goes...

I am in need of a formula that would calculate the following scenario: I have a contest whereby contestants can earn additional points by rating other contestants. These reward points would be awarded for every 10 votes (clarification, a vote is a rating), but for every hundred votes the amount that is awarded increases by .5, so you have something that looks like this:
001-100 = 1.0
101-200 = 1.5
201-300 = 2.0
301-400 = 2.5
...
Thus, 125 votes is worth 13 points ((100 / 10 * 1) + (20 / 10 * 1.5), 284 votes would be worth 41 points. So I am trying to find a formula that I could simply plug in the number of votes and it would return the contestant's score. Any help would be sincerely appreciated.

TIA.
Welcome to Math Help Forum!

I don't know what tool you propose to use to 'plug in' the contestant's score. I have used Excel and have a formula using 3 nested IF's that works up to 400. You can extend this using more IF's, but there will always be a limit to the score that can be entered. The formula assumes that a whole 10 votes is needed for each additional point, and any fractions of 10 are ignored (which is what I think your post means).

Assuming that the contestant's score is entered in cell A1, the formula is

=IF(A1>300, 45+INT(A1/10-30)*2.5,IF(A1>200,25+INT(A1/10-20)*2,IF(A1>100,10+INT(A1/10-10)*1.5,INT(A1/10))))

If you have Excel you could copy and paste this into any other cell to test.

If you want something that will work however big the score you may have to resort to writing some VB code. But that could be done!