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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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What is the value of $-(-6)$?

I know this is not absolute value, so what do the parentheses mean? If it was absolute value, it would have lines so I can rule that out. And I guess I should mention, the question I was asked is "Enter the opposite of this number in the box." So,…
awesomesauce
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Representing a square root as a fraction?

How do I prove that, for example, $\sqrt{3}>\frac{153}{90}$? I can't represent it in any other way than periodic fraction and showing by "Hey, look at the calculator, it's bigger!" doesn't look like a good idea :) Representing as a difference of…
Straightfw
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Absolute value of a complex sum

How can $|{\cos(n x)+i \sin(n x)}|$ = 1 (for $n$ and $x$ positive)? I'm not very good with complex numbers yet, so I would appreciate if someone could please explain how this absolute value comes to be.
sequence
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Order of evaluation of a simple term

If, for example, $a=14$, $b=2$ and $c=7$ and I'm working to (say) three decimal places, should I evaluate the term$$a\frac{b}{c},$$ in the order $$a\left(\frac{b}{c}\right)$$ or$$\frac{\left(ab\right)}{c}.$$ Or should I just say that the original…
Peter4075
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Significant figures reduction of solution

I have a problem which has to be answered using two significant figures from the solution value. My solution value is x = 303.385789245434541 What should my answer be? Thanks
DoubleOseven
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Is multiplication commutative?

Say you have 3 apples and 2 oranges, and you want to multiply these two groups of fruits together to obtain a desired result, for instance: A. You want 3 apples for each orange, so you have 6 apples and 2 oranges. B. You want 2 oranges for each…
user2901512
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Regarding the simplest multiplying methods

I got something method like the simplest multiplying methods when I googling. If you had a number, like 123.456 and you wanted to multiply by 100 you'd just ... Move the decimal point to the right! Exactly. Move it 2 places to the right, since…
gmotree
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Modulus to a range -x to x

I'm trying to solve positions of the planets as described in this paper. Step 3 of the computation starts with "Modulus the mean anomaly so that $-180^o \lt M \lt +180^o$." I understand what that means (we're constraining M to be from $-180^o$ to…
Matthew
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Why negative times negative is positive?

I know that many people would say I don't even know this. But I know it very well that negative × neagtive = positive. But I don't know Why? So kindly give a logical answers.
user83120
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Four lots of sums using only $4$

You need to make exactly four sums using only the number $4$ each time. For example, $4+4+4+4 = 16$ or $4×4-4÷4 = 3$. You can use $+ - × ÷$, square, or square root. Another example: $4^2 × 4 + 4 ÷ 4 = 17$. Now, how do you make the number $18$?
Mal
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Cone mensuration sum

I am a tenth grade student. I am normally good in mensuration, but a question stumped me. The height of a cone is 30 cm. A small cone is cut off at the top by a plane parallel to it's base. If its volume be 1/27 of the volume of the given cone, at…
Mission Coding
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How to convert an interval to different one

I have a variable x in the interval [-30; 30]. I need to convert this interval so x would be in the interval [0; 1]. What I mean is like this: original x: -30 .. -20 ... -10 .... 0 .... 10 .... 20 ... 30 new x: 0 .. 0.16 .. 0.32 ..…
Cobold
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Combinations in Arithmetic progression?

My question actually come from this: Intuitively understanding $\sum_{i=1}^ni={n+1\choose2}$ I was once examining the sum of an A.P series with first term $a$ and common difference $d$ . And this question mentioned above reminded me of same. …
Someone
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Proof that $a^n \ne b^{n+1}, (a, b) \in \mathbb{Z}$

I was wondering if there exists a proof that: $$a^n \ne b^{n+1},$$ $$a, b \in \mathbb{Z}$$ It would really help with a project that I am working on. Thank you very much!
Taylor
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Calculating difference of percentages

Sometimes, in research articles the difference between two percentage is reported directly. How is it right? Example: State A has 75% of people of X kind. State B has 80% of people of X kind. The difference is generally reported as... The difference…
Stat-R
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