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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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Definition of subtraction

I am trying to grasp the intuition behind the historical construction of negative integers. Can subtraction be defined as follows...? $\forall a,b\in \mathbb{N}: \exists c\in \mathbb{N}: a+b=c\iff b=c-a$
user923938
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Multiplication and sequences

Multiplication can be thought of as repeated addition. For instance, we have $3\times 2=6$ which is equivalently expressed as $3\times (1+1)=3+3=6$ Notice that in this definition of repeated addition, we have a 3 which comes first, to which another…
Kwame Brown
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How to find the number of weeks in the following problem?

Problem: In a camp there were stored food of 48 soldiers for 7 weeks. if 8 more soldiers join the camp lets find for how many weeks it will be sufficient with the same food?​ My approach: 48 soldiers: 7 weeks 1 soldier: $ {7\times 48}$ …
Sofia
  • 31
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calculation of two numbers based on a percentage of original number?

I have a known final number. Lets say that is 100. Also I have a percentage difference between original two number. That is number 1 was 10% more than number 2. How do I find the two numbers. I want to do this for a lot of numbers. So any general…
Ahsan Tech
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3 answers

Basic arithmetic question regarding Remainders. Remainder of -11/-5 is?

Arithmetic Problem: Remainder of $\frac{-11}{-5}$ Approach1 : $\frac{-11}{-5}=\frac{11}{5}$ ; Now, $11=5\times2+1$ Gives remainder +1. Approach2 : $\frac{-11}{-5}$; Now, $-11=-5\times2-1$ Gives remainder -1. According to…
Sahil
  • 674
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Calculate revenue from the margin and profit

Let's say I have a profit of $50$ and a margin of $50\%$. Now I know that the revenue is $150$, despite not knowing the cost, because this is the only possibility for the $50\%$ margin i.e. $Cost * (1 + Margin) = Revenue$ $100 * (1 + 0.5) =…
Ivan
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How do decimal remainders work in terms of long division?

I was taught long division a long time ago, and I had this question. Simple enough so far. But then, instead of writing the remainder, I was taught to turn the answer into a decimal by adding zeroes, like so. And further more. I understand it has…
Blauheim44
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I have a formula to determine a one rep max. How can I derive the reps needed from that formula?

This formula is used to determine the one rep max (how much can you lift once) for a lift (squat, deadlift), based on the weight used and reps performed. 1 rep max = weight + weight x reps x 0.0333 So 15 reps with 100kg would give a 1RM of 149.5…
Ivan
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Arithmetics: Does operation order matter?

Let's say I have $3 \div 2 \times 5$. Why can't $2 \times 5$ be the first step in solving it? Because the result would end up being $3 \div 10 = 0.3$ When the proper result would obviously be $1.5 \times 5 = 7.5$. I know, for a fact, that the ans…
Gustavo Duarte
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How do I apply the technique to solve this problem properly?

Question: Two women, Ganga and Saraswati, working separately can mow a field in 8 and 12 hrs respectively. If they work in stretches of one hour alternately, Ganga beginning at 9 a.m., when will the mowing be finished? Doubt: I tried taking the…
Knowledge Seeker
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How to solve this problem on work done?

A man builds $\dfrac{1}{8}$ th part of wall each day but $20\%$ of the wall built on each day falls down. In how many days will the construction of the wall be finished? My doubt particularly is why we are choosing the unit of work here.…
Nayanthara Thomas
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if $h(x)=x^2+4x+4$ find $h(E)$ if $E=\{ x\in \mathbb R\mid0\leq x\leq1 \}$.

If $h(x)=x^2+4x+4$ find $h(E)$ if $E=\{ x \in \mathbb R\mid 0\leq x\leq1 \}.$ It is one of a process on my task on my real analysis lecture, i just stuck at that solve, don't know what to do and have no reference to solve this problem. Please help…
Faqihah Nur Zahirah Muhammad
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Division properties

Proportionally scaling up or down division terms (antecedent|numerator|dividend & consequent|denominator|divisor) doesn't change the end result (fraction|quotient). Is there a name for this property? ex: 10/5 = 2 after scaling up both terms 100/50 =…
Slev7n
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Determines the numbers removed

Four consecutive even numbers are removed from the set $\left\{1, 2, 3, ..., n\right\}$. If the arithmetic mean of the remaining numbers is 51.5625, determine the value of n and which numbers are removed: Attemp: $ 515625= (1+1+(n-1) \cdot r) \cdot…
Lambert macuse
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Is it true for every prime power $q$ that $q-1 | q^r - 1$?

Suppose $q$ is a prime power, $r$ is some positive integer. We can construct the field $\mathbb{F}_q$ where there are $q-1$ non-zero elements. The relation $x\sim y \iff y \text { is a (non-zero) scalar multiple of } x$ in the set of nonzero vectors…
Jun Xu
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