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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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How to understand the principles of the rule of three? By the way, who invented it?

I'm looking to learn all the basic math now, because now I'm an adult math looks much more interesting and easier than ever! As I saw no exact answer for my doubt here on Math SE I resolved to ask this question, which is about the rule of three. For…
Ezequiel Barbosa
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Mathematical operations on tolerances

This question is about manufacturing tolerances; for instance, a manufactured component expressed as "$5 \pm 0.3\,\mathrm{in}$" may acceptably be no larger than 5.3 in and no smaller than 4.7 in. I know how to perform mathematical operations on…
Ryan Kennedy
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Standard way to divide numbers of base other than 10.

I have some homework where I am supposed to divide two numbers that are base 5 or 3. And I did it. I basically converted the numbers to decimal, divided, and then convert the result to the original base. That seems to work. But also seems a bit…
Saturn
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First 10 digits of large sum

There is a debate about this Project Euler problem in the discussion thread for the problem. The debate is whether you only have to add the first 12 digits of each number in order to get the answer. For the particular question, it works fine if you…
ktm5124
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Can I have a trailing dot at the end of a number?

Is 12. a valid way to say 12.0 I was trying it with python. If I say a = 12., python will treat a as 12.0. So I was wondering if it is a valid way to represent a floating point number?
Ranjith Ramachandra
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Is there any formula for number of divisors of $a \times b$?

Let $a$ and $b$ be two numbers, Number of divisors of $a$ is $n_1$; Number of divisors of $b$ is $n_2$; How to find the number of divisors $N$ of product $a \times b$ by using known number of divisors of factors $n_1$ and $n_2$? If $a = 20$ and…
sridhar3525
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A Very Short Question On Surd Notation{Square Root}

What makes $\sqrt[7]{9}$ = $9^\frac{1}{7}$ Can this be explained using laws of indices?
alok
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On the priority of arithmetic operations

Could someone explain the difference between these two problems: 6:2(2 + 1) and 6/2(2 + 1)? The first one should be read as $$\frac{6}{2(2 + 1)} = \frac{6}{6} = 1$$ while the second is actually $$\left(\frac{6}{2}\right) \times (2 + 1) = 3 \times 3…
parkhyeyoo
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Tratchenberg Division Method

$ 743567 \div 256 =$? I get the following method: $ 7 4 3 5 6 7 \div 256 = 2$ __24, 7, 23, And since $23 \div 2 > 9$, I choose $23 \div 3$ to get: $ 7 4 3 5 6 7 \div 256 = 27$ __24, 63 7, 23, 52 Then since $52 \div 2 > 9$, I have to…
Daniel Maher
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Proving square of nonzero integer is natural number

I am learning proofs with $\mathbb N$ and have this proposition: Let $m \in\mathbb Z$. If $m \ne 0$, then $m^2 \in\mathbb N$. Previously, I have proven: For $m \in\mathbb Z$, one and only one of the following is true: $m \in\mathbb N$, $-m…
Johnathan
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Pedro's barn and how to find constant

"In Pedro's barn, the number of mice is inversely proportional to the number of cats. When he owned 5 cats, there were 48 mice in the barn. He increased the number of cats to 8. Based on the increased number of cats, how many mice are in the barn?…
Dana
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Finding product without working it out

What's the easy way to find the solution for the below problem without actually multiplying the numbers: $$(24 * 24) - (16 * 16)?$$ I tried multiplying the numbers but that is a long way. The answer is in the below format A) $(8 \times 8)$ B) $(40…
Rishi
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What is it called and how it works?

If I borrow from two of my parents 50 dollars and spend 45 dollars at the store, I am left with 5. On my way home, I borrow to my friend 3, now I am left with just 2. I return home and give 1 to my dad and 1 to my mom, so I owe them 48 in total. And…
user3143951
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Mathematical arithmetic rounding $1$

What is an example of $4$-digit arithmetic rounding: $ \text{ }\\ \text{a)}\\ 11.2468 = 11.25\\ \text{ }\\ \text{b)}\\ 0.25632 = 0.256\\ \text{or}\\ 0.25632=0.2563\\ $ Can you explain what is correct in example $\text{b)}$?
user2534252
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Why do consecutive triangular numbers in pairs like $6$ and $10$ always add up to a perfect square?

I was a bit surprised by this when I thought of it. Look here: $$001, 003, 006, 010, 015, 021, 028, 036, 045, 055$$$$004, 009, 016, 025, 036, 049, 064, 081, 100$$As you just saw, $15$ and $21$ add to make $36$, a perfect square, and $36$ and $45$…
ReliableMathBoy
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