Split students into groups. It does not matter if each group has the same number of students so long as they are in groups of even numbers. Hand out one chocolate bar to each group and explain that the bar is for the entire group. Ask them to unwrap the chocolate and begin breaking it up for everyone in the group. Be sure to remind them not to eat the candy until you give the OK. Explain to the children that what they have done is break a whole into parts of a whole. For example, each member of a group of six now holds one of six pieces of an entire candy bar. Chocolate works well for this exercise because many manufacturers segment the bars into smaller squares. For a healthier choice, try using tortillas or peeled oranges.
Give children paper plates, crayons or pencils and safety scissors. Have the children decorate their plates as their favorite round food. If they can't think of anything, then suggest pizza, cookies, pie or a birthday cake. Show the children two paper plates that you have prepared before the lesson. Ask them to pretend that all the plates are yummy food items and that you want to share half of yours with your best friend. Take your scissors and cut one of the plates into two unequal halves. Ask the children if you cut the pieces the same size. Show the difference by overlapping the pieces. Now model the proper way to make a half with the second plate. Ask the children to do the same.
If children have mastered the concepts of vowels and consonants, then you have a great opportunity to merge reading skills with math. Give the children a list of words of differing lengths. Have them count the number of letters in each word, giving them denominators. Instruct the children to count out the number of vowels and consonants in each word, giving two numerators to put above the denominators. For example, Apple has five letters, two of which are vowels and three of which are consonants, so two-fifths of the word comprises vowels. You can make your word list for this activity as simple or as complicated as you wish.
Take some pieces of construction paper and cut them into strips of equal length and height. Take a marker and segment the strips into different fractions. Make sure that all the fractions in a strip equal 1, the value of a full strip. For example, segment a strip into four pieces and write 1/4 in each segment. Do this for different values, such as 1/2, 1/3, 1/4, until you think you have made enough. Cut the strips along the segment lines and put some segments into small storage bags, making sure that no bag has enough pieces to equal 1. Include one uncut strip, labeled 1, with each bag for comparison. Hand out the bags to the children and ask them to play a game in which they must trade their pieces with fellow students until they have a full strip that equals 1. The first to get to 1 is the winner of the game. Explain that even though their segments aren't necessarily the same size, when brought together, they equal one whole.