Math Background

Lesson: Identifying Shapes and Matching Parts
Developing the Concept

When children have a basic understanding of fractions and equal parts, they can apply their knowledge to learning about probability.

Materials: circles, squares, and triangles cut from construction paper; paper bag

Prerequisite Skills and Concepts: Children should be able to identify and name plane shapes.

Preparation: Have children watch as you place two squares and a circle in a paper bag.

  • Ask: If I don't look, what shape do you think I'll take out of the bag?
    Discuss children's responses.
  • Ask: Why do most of you think that I will take out a square?
    (There are more squares than circles.)
    Take out a shape and discuss the result. Put the shape back in the bag and repeat three times. Make a tally of the results. Then put in 1 more square and 2 more circles.
  • Ask: How many of each shape are in the bag now?
    (three squares and three circles)
  • Ask: What shape do you think I will take out? Why?
    Children should understand that it is equally likely that you will pull out a circle as a square. Take out a shape and talk about the results. Continue the activity with different numbers of squares and circles.

Wrap-Up and Assessment Hints
To informally assess the children's understanding of halves, thirds, and fourths, as well as of equal parts, cut paper circles in two, three, or four equal parts. Have children reassemble the circles and identify the number of equal parts for each. Have them write the corresponding fractions.


Houghton Mifflin Math Grade 1