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Python

Posted by Jordan Siu
Jordan Siu
10,042 Points

What am I not understanding from %?

For those familiar with the book, I'm doing ex3.py from Learn Python the Hard Way. My code is fine and dandy (minus the floating points, but that's for another topic) but what I can't seem to comprehend is %. I've never been very good at math and can't wrap my head around it but I'm hoping that someone could dissect the logic in this fairly similar but different equation.

Why is it that 100 - 25 * 6 % 4 = 98 Why not 95? 100 - ((25*6) % 4) 100 - ((150) % 4) If the remainder of 150 / 4 is 5 how is it that I'm getting 98?

What am I missing?

Robert Uhler
Robert Uhler
3,637 Points
Robert Uhler
Robert Uhler
3,637 Points

Not quite sure how you are getting to 98 or 95 but the first problem is your calculation of the remainder. 150 % 4 is not 5 but 2. The remainder is 2. Perhaps this is where you issues lies. 150/ 4 == 37 R2

1 Answer

Steven Parker
Steven Parker
229,732 Points
Steven Parker
Steven Parker
229,732 Points

The "remainder" is what is left over after division. It will always be smaller than the operand. So "anything % 4" can never be larger than 3, and certainly not 5.

Here are some examples: 

0 % 4 = 0          148 % 4 = 0
1 % 4 = 1          149 % 4 = 1
2 % 4 = 2          150 % 4 = 2
3 % 4 = 3          151 % 4 = 3
4 % 4 = 0          152 % 4 = 0
Jordan Siu
Jordan Siu
10,042 Points

Oh man thanks, I finally get it. I was going above and beyond from what I was meant to do.

So to simplify things, the first remainder I get is what I'm meant to take?