Math Investigations

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Chapter 2

Part 1: For activity in Teacher's Edition, page 26

Students can practice their research skills by finding the number of each instrument in their state's orchestra. Or you might provide them with the data sheet of information about the Atlantic Symphony Orchestra and the Cleveland Orchestra found on the Activity page (PDF file).

Data Sheet

If you use the data that we have provided, ask the students to share how they rounded the number of each kind of instrument to the nearest ten.


Atlanta Symphony Orchestra
Atlanta, Georgia

Instrument Number Number Rounded to
the Nearest Ten
Violin 32 30
Viola 11 10
Cello 10 10
Bass 8 10
Horn 5 10
Percussion 2 0

The Cleveland Orchestra
Cleveland, Ohio

Instrument Number Number Rounded to
the Nearest Ten
Violin 34 30
Viola 11 10
Cello 12 10
Bass 9 10
Horn 6 10
Percussion 4 0

If students have researched their own data, have them share what they have found about the number of different kinds of instruments in their state's orchestra. Have them show how they rounded the numbers to the nearest ten.

Part 2: Be an Investigator

A good time to do this investigation is after Lesson 1 on comparing numbers.

Introducing the Investigation

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

Make sure that students understand that they need to choose the greater of the two numbers needed of any item.

Put students in groups of 2 to 4 students to work on the investigation. Provide students with the Description of Investigation and Student Report (PDF file).

Doing the Investigation

Have students share what they decided to order and tell how they made their decisions.


Instrument Number Needed
Violin 31
Viola 10
Cello 12
Bass 9
Chairs 506

Student Report

The letter back to Mr. Van Horten gives students an opportunity to write about what they have done, thus communicating about mathematics.

Houghton Mifflin Math Grade 3