21 st century lessons writing algebraic expressions lesson 2 1
TRANSCRIPT
Warm Up
Agenda
2
1) Sally made 20 more shots than Kevin, k. Write an algebraic expression to represent how many shots Sally made.
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.
3) What were the key words that helped you write the algebraic expressions for the problems above?
k+20 20+kor
68 – c
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.
Agenda:
1) Warm Up
2) Launch
3) Explore 1
5) Practice6) Assessment
3
Agenda
Marvin’s Math- Whole Class
Marvin’s Math Part 1- Whole Class
Marvin’s Math Part 2- Whole Class4) Explore 2
Class Work- Partners
Individual
Exit Slip- Individual
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.
Launch- Marvin’s Math
Agenda
4
Agenda
4
Pick a number,Marvin’s Math
add two, multiply by five.
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.
Let’s get a few volunteers.
Agenda
5
Agenda
5
Pick a number Marvin’s Math
, add two , multiply by five.
What was everyone’s result using 18?
Turn and talk: Is Marvin’s expression correct? Explain your reasoning.
5218
Great! Everyone’s response is 100. This is my numerical expression using the number 18.
Explore- Marvin’s Math: Part 1
6
Turn and talk: Is Marvin’s expression correct?
5218 No! What do we need to do in order to make this expression equal 100?
5)218( Hint
Agenda
Explore- Marvin’s Math: Part 1
Numerical Expression.
8
Agenda
Our goal is to write this as an
Pick a number, add two, multiply by five. Marvin’s Math
Explore- Marvin’s Math: Part 1
Algebraic Expression.
(182)5Numerical Expression
(102)5
(12)5If 10 is picked
If 1 is picked
5)2( x
9
5)2( x
How do you think we should write as a written expression?
)2( xLet’s break it down into 2 parts.
The sum of a number and two.
Algebraic Expression
The word sum prompts you to add first.
The sum of a number and two, times five.
Next we combine the two parts.
Agenda
Explore- Marvin’s Math: Part 1
Our next goal is to write this as an Written Expression.
10
10)4( x
Ex. 1 Write a for
Four times the difference of a number and six)6(4 x
Ex. 2 Write an for
5)2( xAlgebraic Expression Written Expression
The sum of a number and two, times five.
Practice problems
The sum of a number and four, divided by ten
)6(4 xor
Agenda
Explore- Marvin’s Math: Part 1
OBJECTIVE ALERT
written expression
algebraic expression
Explore –Marvin's Math: Part 2
11
Agenda
30 less than x
x30
Marvin knows 30 fewer math tricks than his friend.
30x Here are 2 possible Algebraic Expressions.
Which is correct?Lets go back to our basics to figure it out…
Here is the showing the number of tricks Marvin knows.
a) b)
written expression
12
1. What is 30 less than 50?
Turn and Talk: When you see “less than” in a written expression, what is important?
What did you do to get your answer?
2. What is 30 less than 72?
3. What is 30 less than 56?
4. What is 30 less than x?
Agenda
Explore –Marvin's Math: Part 2
2050 - 30
4272 - 30
2656 - 30
x - 30
13
Agenda
30 less than x
x30
Marvin knows 30 fewer math tricks than his friend.
30x Here are 2 possible Algebraic Expressions.
Here is the written expression showing the number of tricks Marvin knows.
a) b)Correct Answer
Explore –Marvin's Math: Part 2
Practice- Class Work
14
Agenda
Name__________________ Date____________
Class Work Lesson 4
a) five less than three times a number
c) nine times the sum of a number and fifteen
g) The sum of half a number and four
e) one plus the product of a number and five
h) seven less than a third of the sum of a number and two
f) A number less than twenty five
d) The sum of twice a number and seven
b) eight less than the quotient of a number and two
1) Directions: Write an algebraic expression for each.
2) Directions: Write two written expression for each. Use the key vocabulary.
10)9( dh10
a) b)
Let’s do the first one together.
15
Agenda
Name__________________ Date____________
Class work lesson 4
a) five less than three times a number
c) nine times the sum of a number and fifteen
g) The sum of half a number and four
e) one plus the product of a number and five
h) seven less than a third of the sum of a number and two
f) A number less than twenty five
d) The sum of twice a number and seven
b) eight less than the quotient of a number and two
1) Directions: Write an algebraic expression for each.
2) Directions: Write two written expression for each. Use the key vocabulary.
10)9( dh10
a) b)
Let’s do the first one together.
n3 5 Important!!!!Identify theoperation(s) by underlining key words.
Practice- Class Work
Practice- Class Work Summary
16
Agenda
Name__________________ Date____________
Class Work Lesson 4
a) Five less than three times a number
c) Nine times the sum of a number and fifteen
g) The sum of half a number and four
e) One plus the product of a number and fiveh) Seven less than a third of the sum of a number and two
f) A number less than twenty fived) The sum of twice a number and seven
b) Eight less than the quotient of a number and two
1) Directions: Write an algebraic expression for each.
2) Directions: Write two written expression for each. Use the key vocabulary.
10
ce)
h10a)
)13(7 nc)
)10( hg g)
10)9( db)
122 xd)
)13(2 nf)
Assessment-Exit Slip
31
Agenda
1) 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.
n93) Write an algebraic expression for
Ten less than the sum of a six and a number
A number less than nine
)8(3 n
10)6( x