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.

6283 questions
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change in relative distance from d1 to d2 where d1>d2

Two cyclists start from the same place to ride in the same direction.A starts at noon with a speed of 8km/hr and B starts at 2pm with a speed of 10km/hr.At what times A and B will be 5km apart ? My thought process: As A starts early at 12 so it will…
jammy
  • 131
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$A$, $B$, $C$ do a job $6$ hours faster than $A$ alone, $1$ hour faster than $B$ alone, and in half the time needed by $C$ alone. ...

Three men $A$, $B$, $C$ working together can do a job in $6$ hours less time than $A$ alone, in $1$ hour less time than $B$ alone, and in one-half the time needed by $C$ when working alone. Then $A$ and $B$ together can do the job in how many…
user160370
  • 415
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What order of operation should I use calculating $2^3 \times 4 - 6 \times 3 ÷ (4 + 3) - 16 ÷ 4$?

I am struggling if I should use PEMDAS or BODMAS in this equation. What is the right method to get around these type of equations? $$2^3 \times 4 - 6 \times 3 ÷ (4 + 3) - 16 ÷ 4 = \ ?$$
Janine
  • 65
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Is there one method of adding and subtracting without a calculator?

One can on a sheet of paper, without a calculator, add two numbers or subtract two numbers, each with it's own method. This is second grade maths. However, is it possible to solve both these with a third and universal method? It can be more complex,…
Friend of Kim
  • 292
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Sum of some place digits in a product

If $x$ is the tens place digit and $y$ is the ones place digit of the product $725278\times 67066$, what is $x+y$? I have no idea how to even approach this.
MathScratch
  • 123
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Distributive Property: How come I get a different answer by distributing than by solving inside the parenthesis first?

Consider the closed phrase: $$-(2\cdot2\cdot2\cdot2)$$ If I distribute $-1$, I get: $$-1(2\cdot2\cdot2\cdot2)= -2\cdot-2\cdot-2\cdot-2= 16$$ If I solve in the parenthesis first: $$-(2\cdot2\cdot2\cdot2)=-(16)=-16$$ Aren't both of these valid…
General Nuisance
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How many significant figures are there after $96$ is correct to $1$ significant figure?

The result of correcting $96$ to $1$ sig. fig. is obviously $100$. Yet, are the two zeros place holder? In that case, I find the following question and answer given by the textbook interesting. It is given that the approximated number of elastic in…
Nighty
  • 2,152
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Need to determine the formula to work out a reduction percentage

We currently calculate a value for a business function as follows; Inputs: A list of values such as; 12 12 6 12 We then add 1 to each of these values and we have values as follows; 13 13 7 13 For each of these we calculate another value using y…
Shaun
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Asymmetry in interpreting integer multiplication

This is a very basic / fundamental question about arithmetic. Multiplication of natural numbers can be thought of as repeated addition, which amounts to "copying" a given number of times. For example, $2 \times 3$ can thought of as the number $3$…
Roland
  • 276
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cant understand this basic division

My long division of $0.5$ into $2.5$ gives the answer $4.1$ , but $0.5 \times 4.1$ does not equal the dividend of $2.5?$ so what gives here?
jitterbug
  • 43
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Adding sine waves of different phase, sin(π/2) + sin(3π/2)?

Adding sine waves of different phase, what is $\sin(\pi/2) + \sin(3\pi/2)$? Please could someone explain this. Thanks.
Sami
  • 169
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Intuition of units: 6 chocolates $\div$ 2 friends = 6 $\times \frac 1 2$ units of what?

I understand that $ \frac {6 \text{ chocolates}}{2 \text{ friends}} = 3 \text { chocolates per friend}$, but what are the units involved if I rearrange this as follows? $$6 \times \frac 1 2 = 3$$ $6$ still seems to be chocolates, $3$ seems to be…
mellow-yellow
  • 509
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Exponents Order of Operation

I'm still confused about order of operations on exponents: Is $x^{a^b}$ equal to $x^{(a^b)}$ or $(x^a)^b$? *Hmm... $x^{a^b}$ has the source of x^{a^b}. Whenever I try x^a^b, it requires me to "clarify by using braces".
Mateen Ulhaq
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Why do mathematicians need to define a zero exponent?

I think a zero exponent can be defined logically from various premises; We can define an exponent as the number of times the base "appears" in a multiplication process. Thus: $2^3 = 2*2*2 $, $2^1 = 2 $, $2^0 = ( )$ doesn't appear at all. …
Khalid T. Salem
  • 421
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Do you think there's a market for maths games beyond simple arithmetic?

I recently created a game for android. I wanted to find out if there's actually someone who would play something like Pythagoras' theorem based game like this: https://play.google.com/store/apps/details?id=com.rizn.pythagoras I have some more ideas…
richard.pi
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