Secondary School Educators/Maths Question

Advertisement


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

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

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

All Answers


Answers by Expert:


Ask Experts

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.

Organizations
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

Publications
Keypost, July 2003

Education/Credentials
Certified E-Rate Management Professional

©2016 About.com. All rights reserved.