Math Background

Lesson: Fractions and Probability
Introducing the Concept

Before children learn to partition “wholes” into equal parts, talk about the concept of “fair shares.” Discuss with children when and why they share things that are the same size and shape. Guide them to connect the concepts of equal parts and fair shares.

Materials: drawing paper divided into four sections, crayons, three paper squares of the same size for each child, scissors

Prerequisite Skills and Concepts: Children should have an understanding of equal parts.

Direct children to draw a picture of themselves in the first section of the drawing paper. Ask them to draw a picture of a friend in the next section. Then give each child a square and ask him or her to pretend that it is a sandwich.

  • Ask: How could I share my sandwich so that two children each have a fair share?
    Children may suggest dividing the square into two equal parts. Have them fold their squares to show halves. Have them cut the shape into halves and place one half in each section with a picture of a child.
  • Ask: What could I call each part of the sandwich?
    Children may say that each part is one half. Write the words one half and the fraction one-half on the board. Compare the halves and discuss different ways that children showed halves.
    three squares divided in half, one horizontally, one diagonally, and one vertically
  • Ask: How can we tell that both parts are equal?
    (They are the same shape and size.)
    Then ask children to draw a picture of another friend in the third box. Give each child another square.
  • Ask: How could we divide the sandwich equally for three friends?
    Children should suggest dividing the square into three equal parts. Have them fold and cut their squares to show thirds. Identify and write the fraction.
  • Ask: Did everyone show thirds the same way?
    Discuss the answers.

    Continue the activity for fourths. Have children draw a picture of another friend and divide the square into four equal parts.

Houghton Mifflin Math Grade 1