7 1 Ratios

7-1 Ratios

Write ratios as fractions and determine whether two ratios are

equivalent

Ratios can be written in several different ways.

• 3 to 2• 3:2• 3/2

• What does this mean?• A ratios is usually a part-to-part

comparison. A fraction usually means a part-to-whole comparison.

Quickwrite

We are ordering Alabama and Auburn t-shirts for HMS students.

150 Students at HMS were asked if they prefer Auburn or Alabama. Of 150 students, 100 prefer Auburn

and 50 prefer Alabama. (We aren’t sure what the problem is with those

last 50.) We have to decide how many of each shirts to order.

Of 150 students, 100 prefer Auburn and 50 prefer Alabama.

• How would you compare student preferences for Auburn or Alabama?

Decide if each statement accurately reports results of the HMS survey

1. At HMS, 1/3 of the students prefer Alabama to Auburn.

2. Students prefer AU to AL by a ratios of 2 to 1.3. The ratios of students who prefer AL to AU is

1 to 2.4. The # of students who prefer AU is 50 more

than the # of students who prefer AL.5. The # of students who prefer AU is two times

the # who prefer AL.6. 50% of the students prefer AL to AU.

Compare statements 4 and 5. Which is more informative? Why?

4. The # of students who prefer AU is 50 more than the # of students who prefer AL.

5. The # of students who prefer AU is two times the # who prefer AL.

Which statement would best convince people that AL is most popular? WHY”?

1. At HMS, 1/3 of the students prefer Alabama to Auburn.

2. Students prefer AU to AL by a ratios of 2 to 1.

3. The ratios of students who prefer AL to AU is 1 to 2.

4. The # of students who prefer AU is 50 more than the # of students who prefer AL.

5. The # of students who prefer AU is two times the # who prefer AL.

Which statement would best convince people that AU is most popular? WHY?

1. At HMS, 1/3 of the students prefer Alabama to Auburn.

2. Students prefer AU to AL by a ratios of 2 to 1.

3. The ratios of students who prefer AL to AU is 1 to 2.

4. The # of students who prefer AU is 50 more than the # of students who prefer AL.

5. The # of students who prefer AU is two times the # who prefer AL.

Write the ratios as a fraction in simplest form.

• 25 to 10

• 6:18

• Your turn:

• 9 to 12

• 27: 15

• 8 to 56

• Determine whether 6:8 and 36:48 are equivalent.

• It is recommended that for every 9 square feet of surface, a pond should have 2 fish. A pond that has a surface of 45 square feet contains 6 fish. Is this the correct number of fish based on the above recommendation?

Determine whether the ratios are equivalent.

• 3/8 and 6/12

• 35 students: 5 adults and

14 students: 2 adults

Converting Units

• Write the ratios 2 feet to 10 inches as a fraction in simplest form.

• 3 feet to 8 inches

• Your turn:

• 4 feet:4 yards

• 15 ounces to 3 pounds

Quickwrite

• How do you use ratios in everyday life?

HOMEWORK

• P 290: 3, 14-29, 33, 41