Math Investigations

Help with Opening PDF Files

Chapter 2

Part 1: For activity in Teacher's Edition, page 30

Students can practice their research skills by finding the birth dates of five famous people. Or you can provide them with the data sheet found on the Activity page (PDF file).

The Chinese New Year is not on the same date every year. It is always in January or February. If students find a birth date that is in January or February, they must find the date of Chinese New Year that year in order to find the animal sign for that person's birth.

If students have looked up their own data, have them share what they have found.

One hint you might give students is that the Year of the Monkey is always a multiple of 12. For example, the 2004 divided by 12 is 167.

If you are using the Data Sheet, ask the following questions when students have finished:

  • Why were Tiger Woods, Sally Ride, and Cesar Chavez all born in the Year of the Hare? (If you start with Cesar Chavez's birth date in 1927 and keep adding 12 you will eventually get 1951, the year of Sally Ride's birth, and 1975, the year of Tiger Woods's birth.)
  • Why were Mia Hamm and Jimmy Carter both born in the Year of the Rat? (If you start with Jimmy Carter's birth date in 1924 and keep adding 12 you will eventually get 1972, the birth date of Mia Hamm.)

Answers for Date Sheet:

Date of Birth of Some Famous People

Name Occupation Date of Birth Chinese Animal Sign
Tiger Woods Golfer December 30, 1975 Hare
Michelle Kwan Ice Skater July 7, 1980 Monkey
Mia Hamm Soccer Player March 17, 1972 Rat
Sally Ride First U.S. Woman in Space May 26, 1951 Hare
Jimmy Carter Former United States President October 1, 1924 Rat
Cesar Chavez Civil Rights Activist March 31, 1927 Hare

Part 2: Be an Investigator

A good time to do this investigation is after Lesson 4 on dividing by two-digit divisors.

Introducing the Investigation

Introduce the investigation by reading aloud the assignment at the top of the first page of the Description of Investigation and Student Report (PDF file), by having one of your students read aloud the assignment, or by having the students read the assignment individually.

Put students in groups of two to four students to work on the investigation. Provide students with the Description of Investigation and Student Report (PDF file).

Doing the Investigation

Suggest to students that they work with the money amount in cents rather than dollars until the end. They can convert an answer in cents to dollars at the end by putting in the decimal point.


Sarah: “I would like to buy 15 Year of the Monkey Stamps. How much will that cost?”

  • Sample Plan:
  • Multiply 15 by 37¢.
  • Convert answer to dollars.
  • Answer: $5.55

James: “If I give you a ten-dollar bill to buy as many Year of the Monkey stamps as I can, how many can I buy? Will I get any change?”

  • Sample Plan:
  • Divide 1000¢ by 37.
  • The answer without the remainder tells how many stamps I can buy.
  • Multiply that number by 37 and convert answer to dollars. Subtract from ten dollars.
  • Answer: James can buy 27 Year of the Monkey stamps with a ten-dollar bill. He will get 1¢ in change.

Miguel: “I have 12 envelopes to mail. Each envelope takes 2 Year of the Monkey stamps. How much money do I need to buy enough Year of the Monkey stamps?”

  • Sample Plan:
  • Multiply 12 by 2.
  • Multiply that answer by 37.
  • Convert cents to dollars.
  • Answer: $8.88

Student Report

The student report gives students an opportunity to write about what they have done, thus communicating about mathematics.

Extending the Investigation

Have students write their own Year of the Monkey stamp problems to solve. Have them trade problems and solve.

Houghton Mifflin Math Grade 6