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.

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How can i get the all digit of a number from 1st to last?

For example: Given number=1234; Failing,how can i separate all the digits from 1st to last?like 1,2,3,4
Ismail Rubad
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How do I calculate a weighted average purchase date?

A farmer bought 100 kg of seed on the following dates: 20 kg on 13-may-2007 (20%) 30 kg on 4-oct-2007 (30%) 50 kg on 31-jul-2008 (50%) How do I calculate the weighted average purchase date? I don't want weighted average age because that changes…
zundarz
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Using the numbers 2, 0, 1 and 3: 1-100

Is it possible to use the numbers 2, 0, 1 and 3 only once and use any arithmetic functions (+, -, *, /, indices, decimals, factorials, trig etc.) to make integers from 1 to 100? For example: 1 = (2*0*3)+1 2 = (0*1*3)+2 3 = (0*1*2)+3 and so…
TinyMusic
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How to Write this question in ordinary number?

I'm doing a Mock Exam and I'm not sure how to do this question. I know how to multiply however I'm not sure how to do $10$ and then the $-3$ inverse. I think it is cubed ($-1000$) however I'm not sure if it is right. This is a non-calculator paper…
user61406
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Geometric series word problem help?

Philip received 75 points on a project for school. He can make changes and receive two-tenths of the missing points back. He can make corrections as many times as he wants. Create the formula for the sum of this geometric series and explain your…
sarah
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Simplify square root in fraction?

Can $\frac{4+\sqrt{40}}{2}$ be simplified to $2+\sqrt{10}$ manually?
gcse
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How can prove that $-(-x)=x$?

I need to prove the following property, but I don't know how: $$-(-x)=x.$$ Please help me. Thanks for your attention.
user100991
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multiplying an dividing irrational numbers and quantifiers

I'm doing a homework assignment, and I am pretty sure that I know which answer they expected, but the problem made me start thinking more deeply about numbers. So if you have an an arbitrary irrational number, is there a number which is equal to…
MVTC
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About a certain signed sum of consecutive integers ($\sum_{k=1}^n k\cdot \varsigma(k)=\sum_{k=n}^{2n} k\cdot \varsigma(k)$)

I hope you will excuse my vague title. Let's define $$\varsigma \ \colon\ \mathbb N\to \mathbb Z\ \colon\ k\mapsto (-1)^{\lfloor \frac{k-1}{2}\rfloor}$$ and $$S(m,n)=\displaystyle\sum_{k=m}^n k\cdot \varsigma(k)$$ Find every integer $n\ge 1$ such…
fosco
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Proving Multiplication by Positive Element

I need help proving this simple fact. If $a,b,c \in \mathbb{Z}$, all $a,b,c>0$, and $a>b$, then $ca>b$. How do I prove this?
Newb
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time and distance problem related to speed

2 workers,One Young And One Old, Live Together and Work at the same office . It takes 20 mins for the young man to walk to office . the old man takes 30 mins for the same distance. when will the young man catch up with the old man , if the old man…
Earthdreams
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How to get average of Arun's weight?

This is an aptitude problem I found in a website, question no 9: In Arun's opinion, his weight is greater than 65 kg but less than 72 kg. His brother does not agree with Arun and he thinks that Arun's weight is greater than 60 kg but less than 70…
Mistu4u
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New hourly rate after a pay raise

Show the correct equation and solve for the indicated items. Jim is earning $12.50 per hour as a cook. He has earned an 8.5% pay raise this year. What will his new hourly rate be? Source:…
laurarodriguez
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Order of operations: problem evaluating an expression

Well I have the expression below can be evaluated in tow different ways according to my knowledge of order of operations: $$\begin{matrix} 3+8\div2\left(10-2^3\right)-7 \end{matrix}$$ OK my try: $$\begin{matrix}…
Mohammad Fakhrey
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Given a distance, two different speeds and time how to determine how far was traveled on each speed.

Given a distance, two different speeds and time how to determine how far was traveled on each speed. For example, if 100m has been traveled in 5 seconds and there was the option to travel the distance by bike and on foot. Speed on bike is 40m/s and…
user1435395
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