N2C8TNp27

 

Answer to Problem 27:
One method Barbara could use is to add 4 and 24, which is 28, then multiply by 1/4.  Her answer would be 7.   Another method Barbara could use is to use the distributive property.  She could take ¼ of 4, which is 1, plus ¼ of 24, which is 6.  1 plus 6 is also 7.

 

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.