What is PEMDAS rule? in Order of Operations

In Number Theory Tutorial ,an expression or string of symbols is intended to represent a numerical value; a properly-formed expression may be evaluated in an unambiguous way. But in practice, an expression with multiple terms and operators may be written without parentheses, in which case the intended value of the expression is determined by convention. When we evaluate the expression is both preceded and followed by an operator such as minus or times, a convention is needed to clarify which operator should be applied first; this rule is known as a precedence rule, or more informally order of operation. From the earliest use of mathematical notation[citation needed], multiplication took precedence over addition, whichever side of a number it appeared on. Thus 3 + 4 × 5 = 5 × 4 + 3 = 23. When exponents were first introduced, in the 16th and 17th centuries, exponents took precedence over both addition and multiplication, and could be placed only as a superscript to the right of their base. Thus 3 + 5 2 = 28 and 3 × 5 2 = 75. To change the order of operations, a vinculum (an overline or underline) was originally used. Today one uses parentheses (). Thus, if one wants to force addition to precede multiplication, one writes (3 + 4) × 5 = 35.We can use order of operations calculator as well.
Mnemonics are often used to help students remember the rules. One common strategy is to build an acronym from the names of the operations. For instance, in the United States, the acronym PEMDAS (for Parentheses, Exponentiation, Multiplication/Division, Addition/Subtraction) is used, sometimes expressed as the sentence "Please Excuse My Dear Aunt Sally" or one of many other variations. In other English speaking countries, Parentheses may be called Brackets, and Exponentiation may be called Indices, Powers or Orders. Also, as Multiplication and Division are of equal precedence, M and D may be interchanged in the mnemonic. (This does not mean that multiplication and division can be performed in any arbitrary order, just that it is wrong to say "M always comes before D", or "D comes before M". See below.) The same comments apply to Addition and Subtraction.

Question:-

Solve 2 - [ (7-6) + (9-19)]

Answer:-

2 - [ (7-6) + (9-19)]

Here we have many signs.

When we have more than one sign ,we have to apply PEMDAS rule

= 2 - [ (1) + (-10)]

We have to solve inside the parenthesis first

Here (+) (-) = -

= 2 - [ 1 - 10]

= 2 - [-9]

Here (-) (-) = +

= 2+9

= 11 is the Answer

A problem on simple interest

Interest is a fee paid on borrowed assets. It is the price paid for the use of borrowed money, or, money earned by deposited funds.Assets that are sometimes lent with interest include money, shares, consumer goods through hire purchase, major assets such as aircraft, and even entire factories in finance lease arrangements. The interest is calculated upon the value of the assets in the same manner as upon money. Interest can be thought of as "rent of money". For example, if you want to borrow money from the bank, there is a certain rate you have to pay according to how much you want loaned to you.

Simple interest is calculated only on the principal amount, or on that portion of the principal amount which remains unpaid.

The amount of simple interest is calculated according to the following simple interest formula:

Let's see a problem on this from 8th grade math worksheets

Question:-

What is the interest earned on # 97500 when rate of interest is 8% and for 5 months?

Answer:-

Here is the solution from answers to math problems



This problem based on simple interest.

The formula for simple interest is

    p x T x R
I= ------------
       100

p= principle=$97500

R=rate of interest =8%

T=Time of year=5 months
=5/12 in years

I=interest amount

We have to put these values in formula

  97500 x 8 x 5
I= --------------
     100 x 12

     3900000
I = ----------
      1200

 I=3250

So the total interest earned on $97500 is $3250.

This is a part of elementary algebra practice .

Problem on mean median mode range

This math help is for mean median mode range worksheets

Mean, median, and mode are three kinds of "averages".

The "mean" is the "average" you're used to, where you add up all the numbers and then divide by the number of numbers.

The "median" is the "middle" value in the list of numbers. To find the median, your numbers have to be listed in numerical order, so you may have to rewrite your list first.


The "mode" is the value that occurs most often. If no number is repeated, then there is no mode for the list.

The "range" is just the difference between the largest and smallest values.

EXAMPLE:-

Find the mean, median, mode, and range for the following list of values:
8, 9, 10, 10, 10, 11, 11, 11, 12, 13

The mean is the usual average:
(8 + 9 + 10 + 10 + 10 + 11 + 11 + 11 + 12 + 13) ÷ 10 = 105 ÷ 10 = 10.5

The median is the middle value. In a list of ten values, that will be the (10 + 1) ÷ 2 = 5.5th value; that is, average of the fifth and sixth numbers to find the median:
(10 + 11) ÷ 2 = 21 ÷ 2 = 10.5

The mode is the number repeated most often. This list has two values that are repeated three times.10 and 11.

The largest value is 13 and the smallest is 8,
so the range is 13 – 8 = 5.

So
mean: 10.5
median: 10.5
modes: 10 and 11
range: 5


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How to solve time and work problems

Topic :- Time and Work

Time and work problems are very important for test preparation when you are out of school for long period .
The time will be given and the amount of work done in that time period needs to be calculated and vice versa .

Here is a simple Time word problem Given ,Which will give an idea of solving workwordproblems
as well.
Question :-

Jim can fill a pool carrying buckets of water in 30 minutes. Sue can do the same job in 45 minutes. Tony can do the same job in 1 ½ hours. How quickly can all three fill the pool together?

Answer:-

Jim can fill the pool in 30 min.
So in 1 min,jim can fill 1/30 th part of pool.

Similarly in 1 min,Sue can fill 1/45th part of pool.

Now 1 1/2 hours = 60+30=90 min.

So in 1 min,Tony can fill 1/90 th part of pool.

Now,if all of them work together,then in 1 min,the part of the tak filled is

   1     1      1
= --- + ---- + ----
  30     45     90

Lcm=90

So by equalizing the deniminators

 1*3      1*2     1*1
------ + ----- + -------
 30*3     45*2    90*1

    3        2        1
= ------ + ------ + ------
    90       90      90

      3+2+1
=    ----------
      90

   6
= ------
   90
   1
= ----
   15

Hence,If they all work together ,The tank will be filled in 15 minutes.


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