Warm Up
OBJECTIVE: SWBAT write algebraic expressions using grouping symbols and the
phrase less than. As well as write written expressions from algebraic expressions.
Language Objective: SWBAT speak with a partner about translations between algebra
and English.
1) Sally made 20 more shots than Kevin, k. Write an algebraic
expression to represent how many shots Sally made.
k+20 or 20+k
2) Damon bought a bin of 68 sour candies. He ate c candies. Write
an algebraic expression to represent how many
candies Damon has left.
68 – c
3) What were the key words that helped you write the algebraic
expressions for the problems above?
Agenda
2
Agenda:
OBJECTIVE: SWBAT write algebraic expressions using grouping symbols and the
phrase less than. As well as write written expressions from algebraic expressions.
Language Objective: SWBT to translate the meaning ‘sum of’ and ‘difference of’ into
algebraic expressions.
2) Launch
Individual
Marvin’s Math- Whole Class
3) Explore 1
Marvin’s Math Part 1- Whole Class
4) Explore 2
Marvin’s Math Part 2- Whole Class
5) Practice
Class Work- Partners
1) Warm Up
6) Assessment Exit Slip- Individual
Agenda
3
Launch- Marvin’s Math
Pick a number, add two, multiply by five.
Let’s get a few volunteers.
What number did you pick? What was your
result?
What did you do first? What did you do second?
Now everyone, let’s use the same number 18.
Agenda
4
Explore- Marvin’s Math: Part 1
Pick a number, add two , multiply by five.
What was everyone’s result using 18?
Great! Everyone’s response is 100. This is my
numerical expression using the number 18.
18  2  5
Turn and talk: Is Marvin’s expression correct?
Explain your reasoning.
Agenda
5
Explore- Marvin’s Math: Part 1
Turn and talk: Is Marvin’s expression correct?
18  2  5
No! What do we need to do in order to make
this expression equal 100?
Hint
(18  2)  5
Agenda
6
Explore- Marvin’s Math: Part 1
Pick a number, add two, multiply by five.
If 10 is picked
If 1 is picked
(18  2) 5
(10  2) 5
(1 2) 5
Our goal is to write this as an



8
( x  2)  5
Agenda
Explore- Marvin’s Math: Part 1
( x  2)  5
Our next goal is to write this as an
Let’s break it down into 2 parts.
How do you think we should write ( x  2) as a written
expression?
The word sum
The sum of a number and two.
prompts you to add
Next we combine the two parts.
first.
The sum of a number and two, times five.
Agenda
9
Explore- Marvin’s Math: Part 1
OBJECTIVE ALERT
The sum of a number and two, times five.
( x  2)  5
Practice problems
Ex. 1 Write a
for
( x  4)  10
The sum of a number and four, divided by ten
Ex. 2 Write an
for
Four times the difference of a number and six
4  ( x  6)
or
4 ( x  6)
Agenda
10
Explore –Marvin's Math: Part 2
Marvin knows 30 fewer math tricks than his friend.
Here is the
showing the
number of tricks Marvin knows.
30 less than x
a) x  30
b) 30  x
Which is correct?
Lets go back to our basics to figure it out…
Agenda
11
Explore –Marvin's Math: Part 2
1. What is 30 less than 50?
20
2. What is 30 less than 72?
42
3. What is 30 less than 56?
26
50 - 30
72 - 30
56 - 30
4. What is 30 less than x?
x - 30
What did you do to get
your answer?
Turn and Talk: When you see
“less than” in a written
expression, what is
important?
Agenda
12
Explore –Marvin's Math: Part 2
Marvin knows 30 fewer math tricks than his friend.
Here is the written expression showing the
number of tricks Marvin knows.
30 less than x
a) x  30
b) 30  x
Agenda
13
Practice- Class Work
Name__________________
Date____________
Class Work Lesson 4
1) Directions: Write an algebraic expression for each. Let’s do the first one together.
a) five less than three times a number
b) eight less than the quotient of a number
and two
c) nine times the sum of a number and fifteen d) The sum of twice a number and seven
e) one plus the product of a number and five
f) A number less than twenty five
g) The sum of half a number and four
h) seven less than a third of the sum of a
number and two
2) Directions: Write two written expression for each. Use the key vocabulary.
a)
10  h
b)
(d  9)  10
Agenda
14
Practice- Class Work
Name__________________
Date____________
Class work lesson 4
1) Directions: Write an algebraic expression for each. Let’s do the first one together.
a) five less than three times a number
3n  5
b) eight less than the quotient of a number
and two
c) nine times the sum of a number and fifteen d) The sum of twice a number and seven
e) one plus the product of a number and five
g) The sum of half a number and four
Important!!!!
f) A number less than twenty five
Identify the
operation(s) by
h) seven less than a third
of the sum
underlining
key of a
number and two
words.
2) Directions: Write two written expression for each. Use the key vocabulary.
a)
10  h
b)
(d  9)  10
Agenda
15
Practice- Class Work Summary
Name__________________
Date____________
Class Work Lesson 4
1) Directions: Write an algebraic expression for each.
b) Eight less than the quotient of a number
and two
c) Nine times the sum of a number and fifteen d) The sum of twice a number and seven
f) A number less than twenty five
e) One plus the product of a number and five
h) Seven less than a third of the sum of a
g) The sum of half a number and four
number and two
a) Five less than three times a number
2) Directions: Write two written expression for each. Use the key vocabulary.
a)
10  h
7(n  13)
c
e)
10
g) g (10  h)
c)
b)
(d  9)  10
d)
2 x  12
f)
2  (n  13)
Agenda
16
Assessment-Exit Slip
1) Write an algebraic expression for
Three times the sum of a number and eight
3(n  8)
2) Write a written expression for the algebraic expression
using less than.
9n
A number less than nine
3) Write an algebraic expression for
Ten less than the sum of a six and a number
(6  x)  10
Agenda
31