Lesson 7

Multiply Fractions by a Whole

Est. Class Sessions: 2

Daily Practice and Problems

Teacher Notes
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TIMS Challenge

This DPP item can be used as a Problem of the Week. Students will need square-inch tiles, a ruler, and grid paper to complete this item.

  1. Students use square-inch tiles to build models.

  2. The line meets the vertical axis at (0 years, 3 squares). That means the creature has 3 squares when it is born.
  3. Possible responses: Going down the column, the first column gets larger by one each row. The column for the number of squares gets larger by 6 squares as you move down a row. All of the numbers are multiples of 3. Going across the rows, if you multiply the age by 6 and add 3, you get the number of squares.
    1. 45 squares; Possible response: I added 6 squares to 39 because 7 is one more than 6 and the creature grows 6 squares each year.
    2. 63 squares; Possible response: I made the table go to 10 rows. I added 6 to each number in the squares column to get the next one. When I got to 10 rows, the size was 63 squares. I used dotted lines on my graph. See graph above.
    3. 123 squares; Possible response: I thought of adding 10 rows after I found the answer to Question 6B. I thought that would be like adding 6 ten times. That would be like adding 60 squares, so I added 60 to 63 and got 123 squares.
    4. 153 squares; I used the pattern I saw going across the rows. I multiplied 25 times 6 and added 3.
      That's 150 + 3 = 153 squares.
  4. Possible response: To get the number of squares, multiply the age by 6 and add 3. S = 6 × A + 3
  5. S = 6 × 25 + 3 = 150 + 3 = 153; Yes, the answer is the same as 6D.
  6. 100 years old; Possible response: I used my formula backwards. 603 − 3 = 600. 600 ÷ 6 = 100 years.

Z. Planet Gzorp

The drawings show the growth of a creature from Planet Gzorp.

  1. Use square-inch tiles or grid paper to build models or draw pictures of this creature up to at least age 6. As you add squares to each year of age, record the data in a table. Put Age in Years (A) in the first column and Size in Squares (S) in the second.
  2. Draw a 4-year-old creature. Name your creature.
  3. Graph your data. Use graph paper or a computer.
  4. At what point does the line or curve meet the vertical axis? What does it mean about your creature when it was born?
  5. Look at the table and graph. Describe any patterns you see. Think about going down the columns and across the rows.
  6. How many squares (S) does the creature have when it is the following ages (A)? Show or tell how you find each age in years.
    1. 7 years
    2. 10 years
    3. 20 years
    4. 25 years
  7. Describe a rule in words for finding the size in squares (S) for a creature of any age (A). Write a formula using symbols.
  8. Use your formula to find the size of the creature when it is 25 years old. Is the answer the same as 6D?
  9. How old is the creature when it has 603 squares? Show or tell how you know.