## Does 625!625! have 156156 zeros at the end?

Someone wrote that 625!‘s last 156 digits are zeros because 125+25+5+1=156. If it’s true that 625! has 156 zeros at the end, how does “125+25+5+1=156” prove it? Answer When you factorize 625!, you are interested in the number of 10s you can divide it by until it is no longer possible to divide evenly. But … Read more

## Do theories and proofs in decimal mathematics work in other numeral systems? Is there a field of mathematics which deals with this question?

The mathematics we use today is based on the decimal system. I was wondering if some or all of these proofs would hold true in other numeral systems. For example binary or hexadecimal. Is there any field which works with questions like this? Answer With rare exception, mathematics works with numbers, not numerals, so the … Read more

## Why is the common positional notation unintuitive

Let’s say I want to invent my own positional numeral system. I start with several symbols representing the smallest amounts: A, B, C, D, E, F. Since I don’t want to have infinitely many symbols and since I’m making a positional system, the symbol representing the next amount will be AA. So I created this … Read more

## What is the name for number systems beyond hexadecimal? [closed]

Closed. This question does not meet Mathematics Stack Exchange guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it’s on-topic for Mathematics Stack Exchange. Closed 2 years ago. Improve this question I know the name of the first couple base n number systems. But what comes after that? … Read more

## How do you convert $(12.0251)_6$ into fractions?

How do you convert $(12.0251)_6$ (in base 6) into fractions? I know how to convert a fraction into base $x$ by constantly multiplying the fraction by $x$ and simplifying, but I’m not sure how to go the other way? Answer I assume you want decimal notation in your fraction. We have (12.0251)_6=(1\times 6^1) + (2\times … Read more

## Solving simultaneous equations with imaginary numbers

Consider the following simultaneous equation: {5z−(3+i)w=7−i(2−i)z+2iw=−1+i What is the simplest way to manipulate one of the equations so that a variable can be eliminated and the equation solved? Answer You do it the same way you do it over the reals. For example, you could solve the first equation for z, z=(7−i+(3+i)w)/5, substitute that into … Read more

## What That Mean “In Base 18”?

i am a programmer who interest in math , lately in palindromic numbers , so if it’s stupid question i am sorry ! i was reading about palindromic numbers in wikipedia , at some point it says In base 18, some powers of seven are palindromic: – 7^3 = 111 – 7^4 = 777 – … Read more

## What exactly is a δ\delta neighborhood

The set of all point x such that |x−a|<δ is called a δ neighborhood of the point a. The set of all points x such that 0<|x−a|<δ in which x=a is excluded, is called a deleted δ neighborhood of a or an open ball radius δ about a. I don’t understand this definition (and because … Read more

## The digit at the hundred’s place of 333333^{33}

I would want to know how to start with the question. And if you get hung up somewhere there’s the answer it’s 5. Any help is appreciated thanks, My approach was to look at the factors to somehow crack the nut. But still in vain. Any help or tip or approach is alright as I … Read more

## Why does casting out 99 and 1111 work to compute remainders?

I found two examples that I’d like to understand: Example 1: Find 112358132134 \mod 9. Solution is: 1+1+2+3+5+8+1+3+2+1+3+4 \mod 9 = 7 \mod 9 = 7 Example 2: Find 62831853 \mod 11. Solution is: (-6)+2+(-8)+3+(-1)+8+(-5)+3 \mod 11 = -4 \mod 11 = 7 My question is: Based on what property we sum the digits of … Read more