Transcript lesson 2-6

Find the sum of
4 and 17.
What is 5 less
than 12?
Jill had eight quarters.
Jack had three times as
many quarters as Jill.
How many did Jack have?
If the 5 players scored a
total of 35 points, what
was the average number
of points scored per
player?
What is 3 less than
twice 10?
Addition Key Words
added to
sum
increased by
more than
plus
Subtraction Key Words
subtracted from
difference
decreased by
less than
minus
less
Multiplication Key Words
multiplied by
product
times
twice (× 2)
doubled (× 2)
Division Key Words
divided by
quotient
ratio of
halved (÷ 2)
7 less than x
“x − 7”
7 less x
“7 − x”
Example 1
Write “9 decreased by 5” as a
numerical expression.
9−5
Example 2
Write “the product of 9 and 5”
as a numerical expression.
9×5
Example 3
Write “a number increased by
2” as an algebraic expression.
n+2
Example 4
Write “the quotient of a
number and 3” as an algebraic
expression.
x
3
Example 5
Write “7 more than the
opposite of a number” as an
algebraic expression.
−n + 7
Example 6
Write each as a mathematical
expression. Bill has $46. How
much will he have if he does
the following?
spends $5: 46 − 5
Example 6
Write each as a mathematical
expression. Bill has $46. How
much will he have if he does
the following?
earns y dollars: 46 + y
Example 7
Write each as a mathematical
expression. Rhonda saves
$18. How much will she have if
she does the following?
saves twice as much:
2 × 18
Example 7
Write each as a mathematical
expression. Rhonda saves
$18. How much will she have if
she does the following?
saves n times as much:
18n
Example 7
Write each as a mathematical
expression. Rhonda saves
$18. How much will she have if
she does the following?
divides her savings evenly
among 3 people: 18 ÷ 3
Example 7
Write each as a mathematical
expression. Rhonda saves
$18. How much will she have if
she does the following?
divides her savings evenly
among n people: 18 ÷ n
Example 8
Write “3 more than twice a
number” as an algebraic
expression.
2n + 3
Exercise
If the letter n represents a
positive integer, write an
algebraic expression for each
of the following.
the next consecutive integer:
Exercise
If the letter n represents a
positive integer, write an
algebraic expression for each
of the following.
an even integer:
Exercise
If the letter n represents a
positive integer, write an
algebraic expression for each
of the following.
an integer 2 more than n:
Exercise
If the letter n represents a
positive integer, write an
algebraic expression for each
of the following.
an odd integer:
Exercise
If the letter n represents a
positive integer, write an
algebraic expression for each
of the following.
the integer preceding n:
Exercise
If the letter n represents a
positive integer, write an
algebraic expression for each
of the following.
three consecutive integers:
Exercise
Three boys decide to share a
pizza and divide the cost.
They will each leave a $0.50
tip. Write an expression for
how much each boy will have
to pay.