Math Investigations

Help with Opening PDF Files

Chapter 2

Part 1: Home and School Investigation

Send the Letter to Family (PDF file) home with each child. You can begin using the groups of objects after Lesson 3. Choose groups of six or less objects anytime after Lesson 3. Choose groups of seven or eight objects anytime after Lesson 6. Each day choose several groups of objects and have the child who brought them in present them to the class. Ask questions such as the following example of 4 blue pencils and 1 red pencil.

  • What did Maria bring? (red and blue pencils)
  • How many blue pencils are there? (4)
  • How many red pencils are there? (1)
  • How many pencils are there in all? (5)
  • How can we show that 4 blue pencils and 1 red pencil make 5 pencils in all? (4 + 1 = 5)

Part 2: Be an Investigator

A good time to do this investigation is after Lesson 6 on ways to make 7 and 8.

Materials

  • counters
  • crayons

Introducing the Investigation

Divide the class into groups of four children. Give each group a slip of paper with the number 4, 5, 6, 7, or 8 on it.

Doing the Investigation

Ask the groups to find as many ways as they can to make their number by adding two numbers together. Tell them that they cannot use zero. Let children use counters to help them find the solutions. Here are all the ways to make each number:

4
2 and 2
3 and 1

5
2 and 3
4 and 1

6
3 and 3
2 and 4
5 and 1

7
6 and 1
2 and 5
3 and 4

8
4 and 4
5 and 3
6 and 2
1 and 7

When the groups have found all of the ways to make their numbers, tell them that they are going to make a funny animal for one of the ways. They will use the color black to draw the animal and then use two colors on the animal to show one of the ways to make that number. For example, for the number 6 they might draw an animal with 4 red legs and 2 blue legs. They can label their animal 4 + 2 = 6.

Display the drawings in the classroom or make a book of the drawings.

Extending the Investigation

Assign the activity with numbers greater than 8.


Houghton Mifflin Math Grade 1