Tables
Graphs
Cross Multiplication
Equivalent Fractions
100
What is the constant (k value)?
x 1 2 5
y 4 8 20
The constant is 4.
100
Is the graph proportional? Explain.
Yes, it has a straight line that goes through 0. The k values are consistent for each point.
100
What is a proportion?
A proportion is an expression or equation that states that two ratios are equal
100
What is the constant of proportionality?
Known as the k value: A number that you multiply with the numerator and denominator.
200
What is the constant (k value)?
x 1 4 3
y 1.5 6 4.5
The constant is 1.5
200
Is the graph proportional?
No, it does not go through 0.
200
Cross Multiply:
3/5 = 15/x
x= 25
200
Are these fractions equivalent? What is the k value?
1/3 and 2/6
Yes! K = 2
300
Is the table proportional? Explain.
No. There is no constant or k value.
300
Is the graph proportional?
Yes, it is a straight line which goes through 0. The k values are also the same for each point.
300
Cross Multiply:
2/9 = x/81
x= 18
300
Are these fractions equivalent? What is the k value?
4/3 and 12/8
No these are not equivalent fractions.
400
How do we find the k value from a table? How do we know if a table is proportional?
We find the k value by finding points on the table and using the formula k= y/x. To know if a table is proportional the k value has to be the same for all the points on the table.
400
What are the two things that a graph has to have in order to be proportional?
1) be a straight line that goes through the origin
2) Pick 3 points, use y/x to determine if they are equivalent
400
Cross Multiply:
x/6 = 48/72
x = 4
400
Are these fractions equivalent? What is the k value?
62/12 and 31/6
Yes! K = 1/2
500
Is the table proportional? Explain.
Yes, the constant (k value) is 2.65.
500
Challenge: What does it mean to go through the origin?
It means going through 0. Origin is another work for 0.
500
Cross Multiply:
12/10 = x/45
x = 54
500
Are the points in this table equivalent?
Yes! 2/3 = 4/6 = 6/9