This topic brings back good old memories of our primary/elementary days in school when we were taught "Arithmetic" and a resounding "State and capital".... "Wow, things have changed!
Reciting through the "Times Table" was something I never liked then because of the long "Metric Arithmetical Tables" that was more of a song....100 metre makes 1 kilometer, 365 days make 1 year, 366 days make 1 leap year and off course the long 2 times 1 two, 2 time 2 four, 2 time 3 six. I liked the State and capital more because of its rhythmic sequence, Sokoto- Sokoto, Ogun-Abeokuta, Niger-Minna, Plateau-Jos!....but today i am glad i did sang those songs using the book below in illustration 1.
I almost forgot this- 30 days has September, April, June and November...
Illustration 1.
Picture source: http://www.nairaland.com/389532/u-did-not-use-exercise
Moving to higher classes, we were then exposed to one of the mathematical rules that turned on my hatred for "Quantitative Aptitude", why because I failed like no man's business and not until i learnt the simple rules behind BODMAS that i began to pass with good grades.
BODMAS is the simple rule guiding the order of mathematical operations and the simple truth why you get some mathematical calculations wrong is because you flaw this rule. Now, let's go back to class as I still remember how the blackboard of St. Bernadette's Primary School, Abeokuta looks like
"Operations" mean things like add, subtract, multiply, divide, squaring, etc. If it isn't a number it is probably an operation.
But, when you see something like...
7 + (6 × 52 + 3)
... what part should you calculate first?
Start at the left and go to the right?
Or go from right to left?
Start at the left and go to the right?
Or go from right to left?
Calculate them in the wrong order, and you will get a wrong answer !
So, long ago people agreed to follow rules when doing calculations, and they are:
Order of Operations
Do things in Brackets First. Example:
 | 6 × (5 + 3) | = | 6 × 8 | = |
48
| ||
 | 6 × (5 + 3) | = | 30 + 3 | = |
33
| (wrong) |
Exponents (Powers, Roots) before Multiply, Divide, Add or Subtract. Example:
| 5 × 22 | = | 5 × 4 | = |
20
| ||
| 5 × 22 | = | 102 | = |
100
| (wrong) |
Multiply or Divide before you Add or Subtract. Example:
| 2 + 5 × 3 | = | 2 + 15 | = |
17
| ||
| 2 + 5 × 3 | = | 7 × 3 | = |
21
| (wrong) |
Otherwise just go left to right. Example:
| 30 ÷ 5 × 3 | = | 6 × 3 | = |
18
| ||
| 30 ÷ 5 × 3 | = | 30 ÷ 15 | = |
2
| (wrong) |
How Do I Remember It All ... ? BODMAS !
B
| Brackets first |
O
| Orders (ie Powers and Square Roots, etc.) |
DM
| Division and Multiplication (left-to-right) |
AS
| Addition and Subtraction (left-to-right) |
The Order of Operations in Excel Formulas
Spreadsheet programs such as Excel and Google Spreadsheets have a number of arithmetic operators that are used in formulas to carry out basic mathematical operations such as addition and subtraction.
If more than one operator is used in a formula, there is a specific order of operations that Excel and Google Spreadsheets follow in calculating the formula's result
The Order of Operations is:
Brackets "( ) "
Orders (Powers and Square Roots, offs)
Division
Multiplication
Addition
Subtraction
An easy way to remember this is to use the acronym formed from the first letter of each word in the order of operations:
B O D M A S
How the Order of Operations Works
1. Any operation(s) contained in round brackets will be carried out first.
2. Second, any calculations involving exponents will occur.
3. After that, Excel considers division or multiplication operations to be of equal importance and carries out these operations in the order they occur left to right in the formula.
4. The same goes for the next two operations – addition and subtraction. They are considered equal in the order of operations. Whichever one appears first in an equation, either addition or subtraction is the operation carried out first.
Changing the Order of Operations in Excel Formulas
Since round brackets are first in the list, it is quite easy to change the order in which mathematical operations are carried out simply by adding brackets around those operations we want to occur first.
As simple as this may sound, using it wrongly has caused many companies to suffer financial loss arising from using bad Financial Models that does not obey the BODMAS rule. As a matter of fact, some employees salary has been wrongly calculated (shortchanged) from wrong use of BODMAS whilst calculating tax, prorated leave allowances and other deductions!
Some experience can be the worst teacher...
Excel-lently yours,
Oladapo Sorinola
07014282477, 07062932708
BB Pin 52E9802D
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