6th Grade Math Textbook, Progress

54 Chapter 1

Evaluate Addition and

Subtraction Expressions

1-11

Evaluate each expression.

1. 30.6
   8.7 2. 18,204
   3619 3. 16.87.530.04


2. j
   42, when j 98 5. 300
   f, when f 250 6. r9.3, when r1.5

Taylor is bowling. He knocks down some of the 10 pins.

How many pins are left standing?

10 
x

What if Taylor knocks down 8 pins?

To determine how many pins are left standing,

evaluate the expression.

So the value of the expression 10 
x, when x8, is 2.

When 8 pins are knocked down, there are 2 pins left standing.

Study these examples.

Evaluate each expression for the given number.

This algebraic expression represents

the number of pins left standing.

w
$3.50, when w$100

w 
 $3.50 Replacewwith$100.

$100 
 $3.50 Subtract.

$96.50

8 mp, when m3.54 and p 18

8  m  p Replacemwith3.54

andpwith18.

8 3.54 18 Add.

29.54

To evaluate an algebraic expression:


Replace the variable with a given number.


Compute to find the value of the expression.

Evaluate 10 
x, when x8.

10 
x Replacexwith 8.

10 
 8 Subtract.

2 value of expression

value of expression

value of expression

1.1

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