I have a 6th grader who is having a hard time with Math . Order of operations is the page for today .Parent that needs HELP !

7 Answers | Add Yours

job518's profile pic

job518 | College Teacher | (Level 2) Adjunct Educator

Posted on

I find that the PEMDAS is the easiest way with the saying Please, Excuse My Dear Aunt Sally. Make sure your student commits this to memory. It is vital to his or her progress through math. Also make sure they understand what each step implies by the use of the 1st letters. I have had many students that could tell me the saying, but could not tell me what it meant they should do.

Also very important - multiplication and division should be completed in the order which they exist in the propblem from left to right. ( addition and subtraction is the same way)

Example : 15 ÷ 3 * 4 = 5 * 4 = 20 NOT 15 ÷ 12 = 1.25

----> many students want to do the "M" first because it comes before "D" in the saying

Example: 12 - 5 + 3 = 7 + 3 = 10 NOT 12 - 8 = 4

Keeping in mind that everything within parenthesis should be reduced to its simplest form before going to the next step. Since this is 6th grade, everything in parenthesis will probably reduce down to 1 number. Then you can do the exponents before proceeding to mult. & div. etc.

I always try to give an analogy that may stick with a student. Think of the order of operations like socks and shoes. IF you are going to wear socks, then you put them on before your shoes. Likewise, parenthesis before exponents, etc. However, you may not always wear socks. So you just put on your sandals. Every problem is not going to require that you do every step of the order of operations. If there are no parenthesis, then go on to exponents, or mult., which everstep comes 1st, and proceed from there.

If you still need some help just repost and I will try to locate some practice or powerpoints that I am sure I have (somewhere).  

 

 

 

 

lorrainecaplan's profile pic

Lorraine Caplan | College Teacher | (Level 1) Educator Emeritus

Posted on

Does your sixth grader know about "Please Excuse My Dear Aunt Sally"?  This is a sentence that has the first letters of the order of operations in a way that is easy to remember: parentheses, exponents, multiplication, division, addition, subtraction.  Most students learn this in elementary school or middle school, but I am so old my students actually taught me this device! 

One way to make the point about the importance of knowing this is to do some problems together using different orders of operation.  Your child will see that you get different answers every time.  This is not a good thing if engineers are making calculations for the space shuttle or a doctor is trying to figure out the right dose of medicine.  The other important aspect of the order of operations is that math is an international language.  While it may be all right for some of us to drive on the right and some of us on the left, it is not all right if mathematicians in Spain are using one order of operations and the mathematicians in France are using another.

It is a good mom who does some research to help her child.  Good luck to both of you! 

bamaji's profile pic

bamaji | College Teacher | (Level 1) eNoter

Posted on

I am sure you will realise the importance of mnemonics to remember the sequence of operations as clearly explained by the earlier posters. But I wish to clarify that the use of either BODMAS or PEMDAS is not binding; the individual student can modify this to include/substitute  phrase with that he will memorise and recall with ease. It is essential to understand the concept to perform these algebraic operations and then you will enjoy doing math! Working out with different problems will help you to grasp this sequence quickly. In a nutshell it is first Brackets, second Exponents, third Division , fourth Multiplication, fifth Addition and finally Subtraction starting from the left going to the right. I am sure you will get it!

neela's profile pic

neela | High School Teacher | (Level 3) Valedictorian

Posted on

Order of operations in mathematics is  to decide  which is to be first and which operation takes priority over the other.

We know that the primary  operations of mathematics are addtion, subtraction, multiplication and division and any thing involng these with some symlos like btacket or paranthesis, power or order or exponents etc.

Bracket is denoted by the symbols: (  ) , [   ] , {    }.

Order or Exponent or Power  is denoted by the symbol:  ^

Division is denoted by the symbol: '/,  on paper and / in computer  .

Multiplication is denoted by the symbol: x on paper and * in computer.

Addtion denoted by the synmbol:  +

Subtraction denoted by the symbol:  -

 

In  mathematical  problems involving all these operations , priority principle is, BODMAS . That is, first priority is  to take up the contents of Bracket and simplify , then go for Order or Exponent, and then the DIvision or Mutiplication, then Addition or Subtractiion.

Some call this mnemonic, BODMAS by the abbreviation ,PEMDAS or PEDMAS, where P stands for Paranthesis or Bracket, and  E for Exponent.But anyway the priority rule is the same.

Division or multiplication are of equal priority.

Addition and subtraction are of equal priority.

Under equal priority level of operations go from left to right,the first come first served principle. Do not choose from the middle.

Practice makes everything easy . Below we give some examples which may help clear confusion. I purposely give such examples where even the math-literates falter, keeping a blind eye over their mistakes.

Example: 10/2*3: First operation: 10/2=5 as divison is a priority. The result is multiplied by 3 . So ,  5*3 =15

10/(2*3): First operation 2*3 =6, as bracket is first operation with higher priority over division. Then 10/6= 1and4/6 =1.6667 nearly.

Example: 5+ 30/10*10 =5+3*10=35.(Mind that this is not equivalent to 5+30/10^2)

Example: 5+30/10^2 = 5+30/100 , the exponent in 10^2 has priority over Division.

Example:200/5*5 =200/5=40. Then 40*5=200

Example 200/5^2=200/25=8.

200/5*5 is not equal to 200/5^2.

Example:( Probably most confusing).

200/10/5: All divisions are of same priority. So go from left to right.200/10=20. Then the result , 20/5 =4. You can't take 10/5 first because , 200/10 comes earlier than 10/5.

Hope this helps.

lsoll098's profile pic

lsoll098 | eNotes Newbie

Posted on

PEMDAS or Please Excuse My Dear Aunt Sally are great mnemonic devices for children to use to solve order of operations expressions. Parenthesis, Exponents, Multiply, Divide, Add, Subtract is the the order. If your child follows this order, they will solve the expression successfully. It is important for them to stay organized and rewrite the expression after each step they evaluate in order for them to follow the next step. 

jg1234a's profile pic

jg1234a | eNotes Newbie

Posted on

PEMDAS
The following expression can also help you to remember this acronym:
"Please Excuse My Dear Aunt Sally"

 

The answer by a graduate student below is WRONG.  Please remember Please Excuse my dear aunt sally

Parenthesis; exponent; multiply, divide, add, subtrack

greatteacher's profile pic

greatteacher | Elementary School Teacher | eNotes Newbie

Posted on

As a teacher, I always teach my students a mnemonic device to help them remember the order in which you solve these types of tricky math problems. Please Excuse My Dear Aunt Sally. It corresponds to the first letter in each of the words and helps you to remember in what order you do what. Please is the first word in the poem so you Do the problem inside the parentheses first. The next word in the poem is excuse. This reminds you that the second thing you do is solve any exponent work. Third, you would multiply, then do any division work, finally you add or subtract. 

I hope this helps!

We’ve answered 318,915 questions. We can answer yours, too.

Ask a question