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Mathematic calculation issue

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Aug 11.2015

1 – ((1624.00/0.56)/2900.00)
instead of giving output 0 (zero) the above code is giving output ‘1.1102230246252E-16’ in php

Someone please help.

Thanks
Saud …

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PHP

2 Comments(s) ↴

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@jedaisoulAug 11.2015 — Hi and welcome to the site.

The problem is the order of calculation, and the rounding errors (which can arise in all computer languages that support floating point calculations). The easy solution is to re-order the calculation:

1 - ((1624.00/0.56)/2900.00)

becomes:

1 - 1624.00/(0.56*2900.00)

Which gives the result 0 because the brackets force the multiplication of the denominator to take place first, then the division and then the subtraction (BOMDAS is a mnemonic to help you remember the order of calculation).

Oops, have I just done your homework?
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@NogDogAug 12.2015 — And just because there's almost always more than one way to do it...
[code=php]
<?php

bcscale(8);
$result = 1 - bcdiv(bcdiv(1624.00, 0.56), 2900);
var_dump($result);

[/code]
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