Mathematics Stack Exchange
Mathematics Stack Exchange

Questions tagged [arithmetic]

Questions on basic arithmetic involving numerical quantities only. Questions involving variable values (other than the result of the operation) should be placed under the (algebra-precalculus) tag. Questions about number theory (sometimes called "arithmetic") should not use this tag and should instead use (number-theory) or (elementary-number-theory).

Arithmetic is defined as operations upon numbers using $4$ main operations along with many others:

addition - the sum of two numbers

subtraction - the difference of two numbers also defined as the addition of negative numbers

multiplication - the area of a rectangle with sides of lengths equal to the two operands

division - the number of times one number can be subtracted from another before equaling zero. Sometimes it will allow decimals and in other cases there will be a remainder left over when a number doesn't go into another evenly

See Arithmetic.

6283 questions
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How to subtract larger hex value from smaller hex value?

In computers we use two's-complement to subtract and it works well, but how does it work for subtraction without two's-complement when subtracting a larger number from a smaller number? 0x0F - 0x13 ------ -1C Doesn't seem to work like…
Adam Thompson
  • 599
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1 answer

Make 0 add to 1 over a specified time

I have the number 0, and every 1/30th of a second, I want to add some number to 0 in order to make it 1 in a specified amount of time. My question is, how do I find the number that should be added to 0 every 1/30th of a second? For example, if the…
vastqud
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For integers $a$ and $b$ , if $a \ne b$, then $ab \ne 1$.

Let $a$ and $b$ are integers. If $a \ne b$, then $ab \ne 1$. Proving the contrapositive: If $ab = 1$ then $a = b$. If $ab = 1$, then there are two possibilities. $a = b = 1$ or $a = b = -1$. No other choice of $a$ and $b$ can make $ab = 1$. In both…
Vinod
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How to find $x$ in this range?

Let $x$ be such that: $602\leq x\leq 608$ $x \bmod 23 = 7$ $x \bmod 13 = 7$ I find $x=605$ by guessing and testing. Is there any better way?
zdm87
  • 99
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Arithmetic mean or average including negative numbers

Hello People at Stackexchange :) First of all: Thank you so much for taking the time to answer my question! I need to calculate weights of a time series which I planned to do by calculating the average or the arithmetic mean and weighting each…
Anni
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1 answer

Expressing division as subtraction/addition

Can one express division as subtraction/addition like one can express multiplication as addition? Like $2 \times 3 = 2+2+2$, can it also be done on division, like saying "$3$ = the number of times $2$ was subtracted from $6$?"
1a2b3c4d
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Represent Budget remaining percentage when Budget is zero

I am creating a budget dashboard where the budget is broken down by capitalized costs and expense costs. Where the budget = 0, but expenses are incurred, how do I calculate and represent the budget remaining %? Using the formula in excel gives a Div…
Anu Sinha
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Solve $5^{2x-1}-6e^{x-1}+1=0$

Find $x\in\mathbb{R}$ such that $$5^{2x-1}-6e^{x-1}+1=0$$ I think that is not possible to find an answer, but I'm not sure.
yemino
  • 814
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Last digit of 1/3

I stumbled upon a very bizarre result when playing with wolfram alpha. According to it, the last digit of $\frac{1}{3} = 7$. Is that true? If yes, is there a mathematical argument for such a result? The reason I require an explanation for such a…
mathnoob123
  • 1,373
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What is the difference between a property and a law?

I am currently learning more about Maths. However, I am struggling to know the difference of a property and a law. Is a property like an attribute to an operation, such as addition and multiplication, and a law is the rules for it applying? Is it…
Steve Woods
  • 103
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Problem sum on time and work

Among 4 persons A, B, C and D. A takes twice as much time as B to complete a piece of work. B takes twice as much time as C and C takes twice as much time as D to complete the same work. If three of them taken as one group and another three as…
Soumee
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Problem related to compound interest arithmetic.

A certain amount of money gets a compound interest of 8800 rupees (Indian Currency) in it's first year and 10,648 rupess in third year. I have to find the amount of money(i.e principal) and rate of compound interest. Also the the interest is…
user533186
  • 15
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Equal Distance between 8 boards to equal 14 ft

I know this is simple math. But my board are not ending with the correct spacing for my pergola. Can someone help me figure this out. 8 boards to cover 14 ft . Do I start on one end and run them straight or start from the middle and work out from…
shawn
  • 1
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sets with sum of 3 digit

How many distinct subsets of the set $S=\{1,8,9,39,52,91\}$ have three-digit sums? I know we have $64$ total subsets, but I don't think that helps us in this question ... does it?
WolverineA03
  • 277
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Simple Elementary algebra

Kelly peeked around the corner and spied $540$ of them not studying. If this was $50\%$ more than Chris spied, how many did Chris spy? My answer was $270$ and marked incorrect. Why? Please help explain. Thank you!
Gabriel Panduro Jr
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