Show the class a whole orange. Tell them you will divide it in half. Cut one piece smaller than the other. Ask if they think you divided it correctly. Point out that fractions must show equal parts. Cut another orange into two equal parts. Hold them up and ask if it shows a correct fraction. Cut each half equally again to display fourths. Have the class brainstorm other things we usually cut into equal parts, such as pizzas, cakes and sandwiches. Write their answers on chart paper to display on a fraction bulletin board.
A pizza manipulative can help students understand that a fraction represents equal parts of a whole. Before this activity, gather plenty of objects for your students' pizza toppings. They can use dried beans, popcorn, buttons, pennies or bingo markers. Place the items in baggies. Prepare enough construction paper pizzas for each pair of students to have nine. Draw lines to divide these pizzas into equal parts from halves through twelfths. Call out a fraction. Ask each pair to cover that portion of the pizza with a topping. For example, tell them to find the pizza divided into fourths and cover two-fourths with popcorn. Walk around and monitor their work.
Ask several children to line up side by side in the front of the class. For example, call up three girls and two boys. Ask the class to count the total number of people standing. Remind them that the denominator in a fraction represents the total number in the group. Write the number on the board and draw a line above it. Next, ask students to identify the number of girls in the group. Write the numerator on top of the denominator. Repeat this activity using different criteria and a different number of students. For example, they could identify how many students in the group are wearing red shirts or how many students wear glasses.
Give each student the same number of M&Ms or Skittles. Don't worry about the colors, as they will each have a random amount of each color. Ask them to identify how many green candies they have in their group. Write their numbers on the board as fractions. For example, if you gave them six candies each, and a student has two green out of the group, write "2/6." Point out that the fraction means two pieces out of six are green. Continue calling out different colors and writing their fractional answers on the board.