writing equations with variables! ms. diehl / october 6, 2011
TRANSCRIPT
WRIT
ING
EQUATIO
NS WIT
H
VARIA
BLES!
MS .
DI E
HL /
OCTO
BER 6,
2011
DO NOWHW OUT ON YOUR DESK!
5.5(x) + 2(y) when x = 3 and y =
2.15(g) – 2 when g = 5
12r x 8b when r= and b=3
2
1
4
1
HW
CHECK!
ACTIVITY
On your DO NOW sheet draw a chart that looks like the following:
# Expression
Letter/Answer Match
I can translate words into math sentences!
REVIEW:
Variable:
A symbol for a number that we do not know yet.
Example: X, Y
A changing quantity
What is a variable in your life?
Substitution:
Replacing variables with numbers
10X + 4Y + 6Coefficient
Constant
Variable
TODAY
We are going to write our own equations
Our equations we write will have VARIABLES and CONSTANTS and COEFFICIENTS!
KEY WORDS
What key words tell us to add, subtract, multiply or divide?
Operation Keywords
Addition
Subtraction
Division
Multiplication
Variable
LETS WRITE AN EXPRESSION:
John makes $6 just for showing up to work every morning. He makes $8 every hour he works.
“every hour” = X (my variable) because I DON’T know for sure what it is
6 = my constant because I DO know what it is.
8 = my coefficient
8X + 6
One more time…What is my variable?What is my constant?
What is my variable?What are my constant(s)?What is my answer?
(3)X+ 14 = 300
SOMETIMES…
We have more than ONE constant
The difference between the number of hotdogs I buy and the number of candy bars I buy is 5.
What is my constant(s)?What is my variable?
X - y = 5
The quotient of x and 3 equals v
What is my constant?What are my variables?
WHITEBOARDS
Some number minus 7 equals 24.
The length of a football field is 30 yards more than its width.
The sum of 8 and f multiplied by the difference of m and 12.
REMEMBER!
What we learn each day builds on what we learned yesterday, last week, and at the beginning of the year!
It is important to stay focused, stay motivated, and work hard so we can all reach our goals of being proficient or advanced on TCAP!
I can translate words into math sentences!
EXIT TICKET!WRITE THE EXPRESSION OR EQUATION. DO NOT SOLVE!
The product of a number plus 7 equals 7.
The number of gallons of gas I buy times the price of $3.28 equals the amount of money I spend a week.
The sum of a number plus 2 equals 17
Three hundred and five squared minus the sum of y and 19.
CHALLENGE: nine less than the total of a number and two