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# Secondary School Educators/Maths Question

Question
evaluate the following arithmetic expressions
3+4*5
5*7-3*4

The Order of Operations is PEMDAS:
Parentheses
Exponents
Multiplication/Division

So we need to do the multiplication before addition or subtraction.

With the multiplication done, we have:
3+4*5=3+20
5*7-3*4=35-12

Now you just do the addition and subtraction:
3+20=23
35-12=23

If we put in some parentheses, we change the order of operations, which will change the result. For example:
(3+4)*5
5*(7-3)*4

Since Parentheses comes first in the order of operations (the P in PEMDAS), we have to do the operations inside the parentheses first, which gets us:
(3+4)*5=7*5
5*(7-3)*4=5*4*4

Which gives us:
7*5=35
5*4*4=80

Secondary School Educators

Volunteer

#### Dan Riordan

##### Expertise

I am an expert in the E-Rate, the Schools & Libraries portion of the Universal Service Fund. I can answer questions for school districts on all topics related to applying for the program and receiving funds.

##### Experience

When the E-Rate was first implemented, I was trained by the NJ Department of Education to assist schools in obtaining funding. Since then, I have worked inside school districts and as a consultant, getting funding for a wide range of schools and libraries.

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E-Rate Management Professionals Association (E-mpa™), Founding Board Member, first Ethics Committee Chairman New Jersey Association of School Business Officials (NJASBO), Associate Member Monmouth County Association of School Business Officials, Associate Member Association of School Business Officials International (ASBO), Associate Member Pennsylvania Association of School Business Officials International (PASBO) New Jersey Association of School Administrators (NJASA), Allied Member International Society for Technology in Education (ISTE), Member Consortium for School Networking (CoSN), Individual Member Federal Communications Bar Association (FCBA), Private Sector Non-Attorney Member Society for Telecommunications Consultants (STC), Consultant Member New Jersey Library Association (ALA), Corporate Member New Jersey Library Association (NJLA), Commercial Member New Jersey Business & Industry Association (NJBIA), Member

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Keypost, July 2003

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