1. Writing Algebraic Expressions
Lesson 4

2. 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.
Sally made 20 more shots than Kevin, k. Write an algebraic expression to represent how many shots Sally made.
k+20
20+k or
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

3. Marvin’s Math 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
Agenda 3

4. Marvin’s Math 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.
Turn and talk: Is Marvin’s expression correct?
Explain your reasoning.
Agenda
Agenda 4

5. Explore- Marvin’s Math: Part 1
Turn and talk: Is Marvin’s expression correct?
No! What do we need to do in order to make this expression equal 100?
Hint
Numerical
Expression.
Agenda

6. Explore- Marvin’s Math: Part 1
Pick a number, add two, multiply by five.
Numerical
Expression
If 10 is picked
If 1 is picked
Our goal is to write this as an
Algebraic Expression.
Agenda

7. Explore- Marvin’s Math: Part 1 Algebraic Expression
Our next goal is to write this as an
Written Expression.
Let’s break it down into 2 parts.
How do you think we should write as a written expression?
The word sum prompts you to add first.
The sum of a number and two.
Next we combine the two parts.
The sum of a number and two, times five.
Agenda

8. OBJECTIVE ALERT Practice problems Explore- Marvin’s Math: Part 1
Algebraic Expression
Written Expression
The sum of a number and two, times five.
Practice problems
Ex. 1 Write a for
written expression
The sum of a number and four, divided by ten
Ex. 2 Write an for
algebraic expression
Four times the difference of a number and six or
Agenda

9. 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.
written expression
30 less than x
Here are 2 possible Algebraic Expressions. a) b)
Which is correct?
Lets go back to our basics to figure it out…
Agenda

10. 20 50 - 30 42 72 - 30 26 56 - 30 x - 30 Explore –Marvin's Math: Part 2
1. What is 30 less than 50?
What did you do to get your answer?
2. What is 30 less than 72? 42
3. What is 30 less than 56? 26
Turn and Talk: When you see “less than” in a written expression, what is important?
4. What is 30 less than x?
x - 30
Agenda

11. 30 less than x a) b) 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
Here are 2 possible Algebraic Expressions. a) b)
Correct Answer
Agenda

12. Practice- Class Work Class Work Lesson 4
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
f) A number less than twenty five
e) one plus the product of a number and 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) b)
Agenda

13. Practice- Class Work Class work lesson 4
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
Important!!!!
Identify the
operation(s) by underlining key words.
f) A number less than twenty five
e) one plus the product of a number and 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) b)
Agenda

14. Practice- Class Work Summary
Name__________________ Date____________
Class Work Lesson 4
1) Directions: Write an algebraic expression for each.
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
h) Seven less than a third of the sum of a number and two
g) The sum of half a number and four
2) Directions: Write two written expression for each. Use the key vocabulary. a) b) c) d) e) f) g)
Agenda

15. Assessment-Exit Slip A number less than nine
Write an algebraic expression for
Three times the sum of a number and eight
2) Write a written expression for the algebraic expression using less than.
A number less than nine
3) Write an algebraic expression for
Ten less than the sum of a six and a number
Agenda