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Back to Write, read, and evaluate expressions in which letters stand for numbers

Write, Read, and Evaluate Expressions in Which Letters Stand for Numbers

Show all steps when evaluating expressions. When substituting a value, write it in parentheses.

Grade 6·21 problems·~35 min·Common Core Math - Grade 6·standard·6-ee-a-2
Work through problems with immediate feedback
A

Recall / Warm-Up

1.

Which of the following uses a placeholder symbol to represent an unknown number?

2.

Which operation does the word 'product' describe?

3.

If x=4x = 4, what is the value of x×3x \times 3?

B

Fluency Practice

1.

Which expression represents 'the sum of nn and 7'?

2.

Which expression represents 'subtract yy from 5'?

3.

In the expression 4x+94x + 9, what is the coefficient of xx?

4.

Evaluate 3x+13x + 1 when x=5x = 5.

5.

Evaluate 3+m23 + m^2 when m=6m = 6.

C

Varied Practice

1.

Which verbal phrase matches the expression 10−k10 - k?

2.

Write the algebraic expression for each phrase.

'The quotient of nn and 4' is written as   ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲   .

'Eight more than twice a number xx' is written as   ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲   .

quotient phrase:
twice-plus-eight phrase:
Diagram showing the expression 3x + 5 with prompt boxes that ask the student to identify its structure without naming the parts for them.
3.

Which statement correctly describes the expression 3x+53x + 5?

4.

In the expression 2(8+7)2(8 + 7), which statement correctly describes the structure?

5.

Evaluate a2−2ba^2 - 2b when a=4a = 4 and b=3b = 3.

D

Word Problems / Application

1.

A store sells notebooks for nn dollars each.

The expression for the total cost of 4 notebooks is   ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲   .

If n=2.50n = 2.50, the total cost is   ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲   .

cost expression:
total cost:
2.

A cube has side length ss units. Use the side length to write an expression for the cube's volume and for the total area of its 6 square faces.

1.

The volume expression is   ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲   .

When s=12s = \frac{1}{2}, the volume is   ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲   .

volume expression:
volume:
2.

The surface area expression is   ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲   .

When s=12s = \frac{1}{2}, the surface area is   ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲   .

surface area expression:
surface area:
3.

A rectangle has length ll and width ww.

The expression for its perimeter is   ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲   .

When l=8l = 8 and w=3w = 3, the perimeter is   ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲   .

perimeter expression:
perimeter:
E

Error Analysis

1.

Priya wrote the expression for 'subtract yy from 5' as y−5y - 5.

What error did Priya make?

2.

Marcus looked at the expression 3x+53x + 5 and said: "This expression is a product of two factors: 3x3x and 5."

What error did Marcus make?

F

Challenge

1.

Evaluate the expression below when a=3a = 3 and b=5b = 5.

a2+b2a−1\frac{a^2 + b}{2a - 1}

2.

The expression 4(2x+1)4(2x + 1) can be described in two ways: as a single product, and by looking at the structure inside the parentheses. Describe the expression at both levels using correct mathematical vocabulary.

0 of 21 answered