Evaluating Numerical Expressions

Evaluating Numerical Expressions

How can you use the Order of Operations to evaluate expressions with decimals?

Fill in the Blanks

Use Order of Operations to evaluate this expression. 

 $10\times\left[3.7+\left(24\div3\right)\right]$  

How can you evaluate expressions with brackets and variables?

 $\left[6\left(x-3.5\right)\right]\div12+4.2$  

 $\left[6\left(x-3.5\right)\right]\div12+4.2$       x = 9.5

• Inside parenthesis first (x - 9.5)

• Substitute 9.5 for x.

• (9.5 - 3.5) = 6

• Rewrite the new expression.

 $\left[6\times6\right]\div12+4.2$  

• Brackets next.

• [6 x 6] = 36

• Rewrite the new expression.

 $36\div12+4.2$  

• Division is next.

•  $36\div12$   = 3

• Rewrite the new expression.

 $3+4.2$  

• Complete addition, the last step. 

• 3 + 4.2 = 7.2

Now, you try.

Remember to follow PEMDAS

Multiple Choice

 $\left(7.8\div2\right)\times12$  

• 46.8

• 117.6

• 69.6

• 15.9

Fill in the Blanks

 $9.2+\left(x\ \times3\right)$  

Evaluate this expression when X = 3

Multiple Choice

 $5.6+\left(3\times9.6-4.8\right)$  

• 20

• 77.76

• 41.28

• 29.6

Fill in the Blanks

 $3^2+\left(7.1-x\times3\right)$  

Evaluate this expression when x = 2

Multiple Choice

 $\left[\left(4.2\times3.4\right)-9.28\right]$  

• 16.88

• 5

• 1.5

• 24.7

Poll

How confident are you with evaluating numerical expressions?

• I feel great!

• I feeling okay.

• I am confused.