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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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Interpretation of sum notation with two parameters

Please excuse the dumb question, but I am totally lost, as I have never seen a sum notation like this before. I am no mathematician, so please excuse me if this is somehow trivial. I am currently looking at implementing a mathematical model. x is a…
A C
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A clock takes 6 seconds to strike 4 times at 4:00. How many seconds will it take to strike 6 times at 6:00?

This is an exercise from a child's elementary school homework. A clock takes 6 seconds to strike 4 times at 4:00. How many seconds will it take to strike 6 times at 6:00? My logic: 6 seconds/4 strikes = 1.5 second/strike. 1.5 seconds/strike x 6…
zundarz
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Inverse compound rule of three explanation

Why when you have to use the compound rule of three that has inverse proportions do you need to invert a fraction and multiply them? Example: A daycare center with 250 children provides 4 portions of food per day to each child for 18 days. If the…
Alejandra
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What are the rules for when I can assume implicit multiplication?

I found a post that mentioned this problem where students get confused when interpreting mixed numbers: Avoiding confusion between mixed fractions and multiplication If a student ask "then when can I assume there is a multiplication sign between two…
Cecilie
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Confusing with basic arithmetics, BODMAS

What is the result of $6\div 2(1+2)$? I simplified the bracket with the $2$ outside first and my final answer was $1$. But I'm kind of getting confused because alpha mathematica evaluates this same expression for $9$. I'm I right? I have no other…
Ernest kwablah Kweitsu
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How Do You Practically Calculate Common Percentages?

I was wondering if there is any quick way of calculating some common percentages such as $15\%$, $25\%$, $50\%$, $75\%$, $90\%$ etc. The best think I could come up with is just simplifying the fraction they represent. So for $75%$, which is…
Camelot823
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What is the fastest way to perform mental division?

I am looking for a way to divide relatively small numbers with high accuracy, though I can't seem to find a way around long division. For instance, say we are trying to convert $7/11$ or $23/17$ to a decimal value. How would we compute a value…
Kai
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If $-2\le x \le 1$ and $-3.4\le x-y \le 3.4$ and $a\le y \le b$ find $a$ and $b$

I have a question, if $-2\le x \le 1$ and $-3.4\le x-y \le 3.4$ and $a\le y \le b$ find $a$ and $b$. that's how I did it: if $-2\le x \le 1$ then $-1\le -x \le 2$ $$-3.4-1\le x-y+(-x) \le 3.4+2$$ $$-4.4 \le -y \le 5.4$$ $$-5.4 \le y \le 4.4$$ but…
Tornike Kacadze
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Time decrease, positive percetange

A simple question but I'll ask anyway, I am writing a report about speed improvements on a particular server task. Originally the task took 4 minutes (240 seconds), it now takes just 10 seconds. How can this be represented as a percentage? I think…
Chris
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Compound Interest and Simple Interest difference insight

The difference between the Compound Interest and Simple Interest on a certain sum at the same rate of interest for the second year is Rs. 32 and for the third year is Rs. 66.56. Find the rate of interest (in %). Solution:- The difference between SI…
Fin27
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Why does dividing zero by a number using repeated subtraction doesn't work?

I know that division can be represented as repeated subtraction, or as an opposite of multiplication. For example, if we divide 6 by 2, we can say what number is multiplied by 2 gives us 6?, which in this case is number 3, and 3 is considered unique…
Ahmed-ibra
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Will Bodmas and Pemdas always yield the same results?

Will Bodmas and Pemdas always yield the same results? The difference is in the order of execution of division and multiplication.
user45664
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To prove and identify pattern in series

Good day to all of you, I don't know if this is basic question or not, and I might have phrase the question wrong, Please pardon me. The question was The numbers {1,2,...,8} can be paired so that the sum of each pair is a square number: 1+8 =9,…
cong le
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Order of operations when solving 47−[83+16−51]÷8+13

I’m a student in Applied Calculations and Measurements. We have a professor who posed the problem: $$47-[83+16-51]÷8+13$$ He solved this as follows: Group $8+13$ Divide $47-[83+16-51]$ by $21$. The answer was 44.71. I believe the answer is…
Ricardo Martinez Jr
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BODMAS or PEMDAS with single number within bracket e.g. : 72÷3(4)+7 operation should be divide first or treat bracket?

I was going though basic school equation and answers by community members were different. They were divided in 2 sections, like given below. Question: $ 72÷3(4)+7$ Option 1: Divide by 3 then x 4 Option 2: Divide by 12 I was wondering even if…
Aditya
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