Question

How to do a modular arithmetic on a calculator? is there a way? I'm using casio fx-95MS

Answer 1

What example problem do you want to work with?

Answer 2

or I could make one up if you want?

Answer 3

for example; 15^5 mod 128

Answer 4

well 15^5 = 759,375

divide this by 128

(759,375)/128 = 5,932.6171875

We don't get a whole number as a result, but we can pull out the whole number part which is 5,932

The fractional or decimal part is 0.6171875 but we'll ignore it.

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Now multiply the whole part 5,932 by the modulus 128 to get: 5,932*128 = 759,296

Then subtract the value of 15^5 which was 759,375 and 759,296

so,

759,375 - 759,296 = 79

So in the end, the remainder is 79 which means

759,375 mod 128 = 79

and

15^5 mod 128 = 79

Answer 5

that example is a bit big, here's a simpler example


60 mod 7 = 4

but how did I find this?

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Step 1) Divide 60 by the modulus 7:

60/7 = 8.57142857142858

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Step 2) Pull out the whole part

whole part is 8

ignore the decimal part

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step 3) Multiply the whole part (8) by the modulus (7)

8*7 = 56

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Step 4) Subtract the previous result from the original number

60 - 56 = 4

The remainder is 4. Therefore, 60 mod 7 = 4

Answer 6

ohh my thank you so mucchh!! all clear to me now! :D

Answer 7

I'm glad it is