6th Grade Math Textbook, Fundamentals

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2-1

Key Concept

Expressions and Variables

A can be a numerical expression or an algebraic

expression.

• A contains numerals and indicates at least one
  mathematics operation.


• An contains one or more variables and
  mathematics operations. It may also contain numerals. A is a
  symbol, usually a letter, used to represent a number.


• A mathematical expression does notcontain the symbols , , or .

numerical expression

variable

algebraic expression

mathematical expression

Carla’s score 6 numerical expression

Dina’s score 6 3 or numerical expressions

Since Bonita’s score is not given, you cannot write a numerical expression
for Bonita’s score or for Anna’s score. However, you can write an algebraic
expression. Choose a variable and explain what it means.
Let bBonita’s score.

Bonita’s score b algebraic expression

Anna’s score b 3 algebraic expression

3 points less than Bonita’s

You can write mathematical expressions from word phrases.

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3

Mathematical Expressions

Objective To translate word phrases into numerical expressions or algebraic expressions

• To translate numerical expressions or algebraic expressions into word phrases

Anna, Bonita, Carla, and Dina are playing basketball. In a game, Carla’s
score of 6 points is three times Dina’s score. Anna’s score is 3 points less
than Bonita’s. Write a mathematical expressionto express each girl’s score.

Word Phrase Mathematical Expression Expression Type

four timesthe sum of five and zero 4(5 0) numerical

two more thanthe product of 8 squared and 10 (8^2 • 10)  2 numerical

halfthe difference between 12 and 7 (12 7) or

1

2

12  7

2 numerical

one thirdthe sum of a number nand 7 (n7)or

n 7

3

1

3 algebraic

the sum of a number nand 8 divided by 2 n 28 algebraic

4 morepoints than Cal scored (c) c 4 algebraic

twice as manyDVDs as Bob has (d) 2 d algebraic