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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Could the fourth root of $1$ be $i$?

Could the fourth root of $1$ be $i$ (or $-i$)? I could show this by doing: $\sqrt[4]{1}$ $\sqrt{\sqrt{1}}$ $\sqrt{\pm{1}}$ $\sqrt{1}$ OR $\sqrt{-1}$ $\pm1$ OR $\pm i$ $\{1, -1, i, -i\}$ Would you include the negative square root from step 3 and…
iggyvolz
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Hi I'm stuck trying to find square footage

Thank you for looking at my question. We're supposed to paint the walls of a room and ceiling twice (x2), the room is 15 ft long by 10 ft wide and 8 ft tall. The teacher is asking us to provide the total area in square feet. The answer given is 550…
anon_ying
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Number of $0$ in great number

For example, $11111111111111100$ ends with $2$ zeros ,when we did know the decimal representation like $100!$ also. I would like a justified answer for the following question . How many $0$ are in the end of decimal representation of $ 100!$? Is…
masmoudihoussem
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Calculating percentages with weights

I've done a search for the answer but still couldn't figure it out. Say for example: Year 1 Result = 80% (Weight:20%) Year 2 Result = 70% (Weight:10%) Year 3 Result = Unknown (Weight:70%) I've not yet got my results for year 3. I want to calculate…
Sabai
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for a friend's birthday, a special birthday card

My question is particulary, my friend will celebrate 27 years (March 19, 1987) and we will offer him the game Diablo 3 : The reaper of Souls . So, I would write on the card all the coincidences between his birth date and the number 3 of Diablo 3 =)…
spacecodeur
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Can't come up with the correct result.(order of operations) Could you please help?

I have the following exercise: $$2\cdot \{100\cdot 3-3\cdot [100-3\cdot (100-3\cdot 33)]\}$$ I've looked into the text book and the correct answer is $18$ but I keep getting $-99$. Here's how I solve it: $$2[100\cdot 3-3\cdot (100-3\cdot…
zizibear
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Column math please help

If I'm adding the sum of £100 +£320+£220+£20+£6+50p+20p+10p+5p+2p, how would I write that using column math. Thanks
Milly
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Distribution of liquid among different capacity cans

There are three cans A,B,C. The capacities of A,B and C are 6 liters, 10 liters and 16 liters respectively. Can C contains 16 liters of milk. The milk has to be divided in them using these three cans only. Now consider the following statements: It…
Sunny
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Why is (-1)(-1) = 1?

I apologize if this is too obvious, but I crave for a reasonable definition/explanation - why is $(-1)(-1)=1$? Something akin to the reason $a^{-1}=\frac{1}{a}$, I.e. because $a^{-1}a^1=a^{1-1=0}=1$, so we get $a^{-1}=\frac{1}{a^1}=\frac{1}{a}$ by…
Morgan Wilde
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Are My Calculations right?

In My Program called More Realistic Galaxy I include all different kinds of stars and I can look up their solar mass limits. I also made it like a midnight blue instead of like black so that if a black dwarf evolves you can actually see it. I have a…
Caters
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How to prove that 12:3 will always be 4

I got this riddle that I just couldnt solve. It's simple, how can you prove that a:b will always be C ? (a, b and c are natural numbers) For example 12:3=4, 4 will be the only solution.
zarko
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compare an integer number without using calculator

we have $\displaystyle a=2^{12}$ and $\displaystyle b=3^8$ and I wonder if exist method to compare them without using calculator.
Gregor
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Alternating sign square sum

It can be seen that $6^2 - 5^2 + 4^2 - 3^2 + 2^2 - 1^2 =21 = T_6$, the sixth triangle number. Prove that the $n$ th triangle number, $T_n = n^2 - (n - 1)^2 + (n - 2)^2- \cdots + 1^2$. Well my solution is : if $n$, and group them into $n/2$ pairs:…
Manal
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Proving an existence

I am completely lost on where to go with this one. Can someone provide help with how to do this? I am trying to understand uniqueness. Here it is: Prove that for every real number x, if x DOES NOT equal 0 and x DOES NOT equal 1 then there exists a…
user131091
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Find $x;y;z\in \mathbb{Z}^+$ such that : $\left\{\begin{matrix} (xy+1)\vdots z & \\ (xz+1)\vdots y & \\ (yz+1)\vdots x & \end{matrix}\right.$

Find $x;y;z\in \mathbb{Z}^+$ such that : $\left\{\begin{matrix} (xy+1)\vdots z & \\ (xz+1)\vdots y & \\ (yz+1)\vdots x & \end{matrix}\right.$ Thanks :) I have tried that : $\left\{\begin{matrix} (xy+1)\vdots z & \\ (xz+1)\vdots y & \\…
Lê Tấn Khang
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