Transcript Evaluating and Writing Variable Expressions

Writing & Describing
Algebraic Expressions
Chapter 2 Lesson 2
Variable:
a symbol that stands for a number.
Examples: a, b, x, y, …...
a
Algebraic Expressions:
group of numbers, variables, and
operations.
Examples: 13 - g
z+2
3x + 8
Add
plus
Subtract
minus
Multiple
Divide
the product the quotient
Combined,
together
the sum
the
difference
subtract
multiply,
times
groups of
divide
total of
*less than
times
increased
by
*more than
decreased
by
fewer than
double,
triple
Twice
each, for
every
per
additional
how much
more than..
of
into
out of
shared
equally
Examples:
3 less than a number
n-3
The sum of 5 and a number
5+b
The product of 7 and y
7y
Rules:
• Write each problem the way you
read the words from left to right.
• “more than” OR “less than”
means flip the problem parts.
Write an algebraic expression for
each word phrase.
1. The sum of eighty-nine and a number.
2. The difference between forty-six
and h.
3. The quotient of twenty and a number.
4. Fifty-five times f.
Write an algebraic expression for
each word phrase.
1. one more than the product of twelve
and a number
Answer: 12p + 1
2. four less than a number n divided by
two
Answer: n ÷ 2 - 4
3. Six minus the quotient of u and two
Answer: 6 – u ÷ 2
Translate each algebraic
expression into words.
1. 3 + n
Answer: 3 more than a number
2. 7h
Answer: the product of 7 and h
3. a – 5 **use the word “less than”
Answer: 5 is less than a
Translate each algebraic
expression into words.
4b – 3
Answer: 4 multiplied by b minus 3
OR three less than the product of
four and b
5. 16g + 12
Answer: The product of 16 and g plus
12 OR Sixteen times g plus 12
4.
Chapter 2 Lesson 3
Function Tables
Evaluate each expression to find the missing
value in each table.
w
w÷4
n
88
1
60
2
100
3
4xn+6
Evaluate each expression to find
the missing value in each table.
n
1
6
7
2n - 2
n
20
5
18
9
25 - n
5
Find an expression for each table.
x
0
72
88
x÷8
0
9
11
n
15
25
35
n + 25
40
50
60
Find an expression for each table.
n
2n
13
26
9
18
30
60
25
50
x
x-2
8
6
4
2
2
0
Combining Like Terms
•
•
•
•
•
•
•
3s + 7 – 4 + 4s – 5s + 8p
Let’s put together things that are alike:
3s + 4s – 5s= 2s
7–4=3
8p
Altogether: 2s + 3 + 8p
Let’s do more
Combining Like Terms
Rules:
• Write each problem the way you
read the words from left to right.
• “more than” OR “less than”
means flip the problem parts.
Translate each algebraic
expression into words.
1. 3 + n
Answer: 3 more than a number
2. 7h
Answer: the product of 7 and h
3. a – 5 **use the word “less than”
Answer: 5 is less than a
Evaluate each expression to find
the missing value in each table.
n
1
6
7
2n - 2
n
20
5
18
9
25 - n
5
Combining Like Terms
•
•
•
•
•
•
•
3s + 7 – 4 + 4s – 5s + 8p
Let’s put together things that are alike:
3s + 4s – 5s= 2s
7–4=3
8p
Altogether: 2s + 3 + 8p
Let’s do more