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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.

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Can an integer "round" to itself?

If I asked "When rounding to the tens place, how many different whole numbers will round to 50?" would the answer be "9" or "10". As in: does "50" "round to itself" (in which case, 10) or does it not count because it doesn't "go anywhere" (in which…
bigfooot
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Can we calculate the percentage of red blood cells which are destroyed per day if we assume that all red blood cells have a lifespan of 120 days?

Approximately 1% of red blood cells are destroyed per day. I was wondering if we could derive this from the assumption that all red blood cells have a lifespan of 120 days. I think we should assume that the concentration of red blood cells is…
Deez Nuts
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Why does the "borrow" algorithm for subtraction work?

I would like to understand how the borrow algorithm for simple subtraction ( base 10, the one we learn when we are kids ) works, does anyone have any material on this? Thank you.
Victor Luiz
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Sig figs and exact numbers

I have a question about sig figs and decimals. If you start off with an exact value like 8.00 m which is 3 sig fig and you multiply by 100 cm so 800 cm. Then you divide by 2.54 cm and get 314.96 in. Because it's 3 sig fig you round to get 315 inch…
cameronm
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Approximation of Sum of square roots of n

I recently came across a puzzle which was asked in an interview. The puzzle requires us to compute sum of square root of first 50 natural numbers without any aid of computer (in fact just in head!). Is there any mathematical way to calculate this…
mea43
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What is a symbolic differentiation of simple arithmetic expressions?

I am making some exercises in my programming book and one is the following: Perform symbolic differentations of simple arithmetic expressions with respect to a single variable. Can somebody explain this to me and perhaps give me some examples?
Geert Van Laethem
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Understanding of a question

The cost of producing a math assessment book is made up of three main components , overhead , type-setting and printing . In $2009$, the overhead cost for an assessment book is $\$1200$ , the cost of type setting a page is $\$18$ and the cost of…
user307640
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problem with dumbbells

how do you resolve this problem? I can´t understand. ¿Which one is the less number of dumbbells that that i need to put in the dumbbells plate of a balance to weight 2709kg if you have a dumbbells collection of 1kg , 4kg ,16kg ,64kg,...? Thanks!
Franzz
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Find an efficient mental estimation algorithm for tips.

Context: let's say we want to compute the total, with tip, approximately, and in our head. What is the best method you can construct to find the following. Given $x \in \mathbb{R}^+$, construct $y$ such that $1.14x \leq y \leq 1.21x$ as…
Steve
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Find math formula to calculate stress on particular system?

I need help in knowing how to calculate "stress level" for the particular system. The data used by the sys is shown as picture. taxonomy table How will it works that each row will have a sensitivity score . For in the table red shows value of 8 out…
asad
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What are the general forms of mutually prime numbers?

One example I came across for two mutually prime numbers is $m(n + 1) + 1$ and $m(n + 1) - n$ for any two $m, n$ natural numbers. Are there any other such procedures for generation of mutually prime numbers? Is there any reference where I can get…
Seetha Rama Raju Sanapala
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number of digits in the square root of a perfect square

number of digits in the square root of a perfect square with n digits is ceil(n/2). We can get convinced of this result by following the division method. My question is, is there analytical proof of this result?
Seetha Rama Raju Sanapala
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Short-cut for computing some large number N (mod 3)

Is it OK to assert that a number (mod 3) is the sum of each of its digit (mod 3), i.e., for an n-digit number represented by a1a2a3...an (mod 3) = a1 (mod 3) + a2 (mod 3) + a3 (mod 3) + ... + an( mod 3) ?
Beedassy Lekraj
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How to simplify this algebraic expression? What is the proper name for this problem?

I am studying for a teacher exam and I am stumped with this problem $3\cdot \frac{(2+6)^2}{6}$ I know that the answer is $32$ because of the answer sheet, but how and why is this the answer? Can I get an example?
tina
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What is the result of $5-0\times3+9/3=$?

Possible Duplicate: Answer of $5 - 0 \times 3 + 9 / 3 =$ What will be the answer of $$ 5-0\times3+9/3 = ?$$ if we follow BODMAS? Please explain each step.
Serious
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