N2C7TNp36

 

Answer to Problem 36:

Melissa started by adding.  You should always do what is inside the parenthesis first, then multiplication, then addition.

 

Rework Problem Correctly

5 + 2 x (3 + 4)

5 + 2 x 7

5 + 14

Correct Answer:          19

 

 

DEFINITION:

properties of operations:  associative and commutative properties of addition and multiplication, the distributive property of multiplication over addition to simplify computations; order of operations should be followed.

                                          Example: 3(3+52)÷7+1 = 3(3+25) ÷7+1 = 3(28)÷7+1=84÷7+1=12+1 =13[1]

Mathematicians have agreed that when there is more than one operation within a problem, the operations should be done in the following order:

    1. Perform all operations that are in grouping symbols
    2. Do all work with exponents
    3. Multiply and divide in order from left to right

Add and subtract in order from left to right[2]


 

[1] National Council of Teachers of Mathematics. (2000). Principles and standards for school mathematics (p. 214). Reston, VA: Author

[2] Chaplin, Suzanne. (1995), Middle Grade Mathematics:  An Interactive Approach. (p. 524). Needham, MA: Prentice Hall Publishers.