While singing traditional counting songs move the correct number of beads on the abacus. For example, sing "10 Little Indians" with the preschoolers. Sing the first line, "one little Indian," and push one bead over. Then sing the next line, "two little Indians," and push over another bead. Invite the children to copy you. At the end of the song, count up all the beads that were pushed over. Use the abacus for other math songs, such as "Yellow is the Sun" or "Five Little Monkeys."
Play a color matching game with the young children. Choose a color on the abacus, such as blue. Ask the preschoolers to find all the other beads that are the same color. Count up all the beads that are the same color together the first time. Invite other children to choose a color to match and then instruct the children to count up the beads.
Create a set of flashcards up to the number 10 for the preschoolers. Write the numbers onto index cards and turn them upside down. Mix them up and instruct a child to choose the top card. Looking at the number on the card, the child pushes over the same number of beads while counting out loud. If the child is incorrect, she is out. The last child is the winner.
A few online websites use the abacus to teach preschoolers about simple math computations. The BBC's website offers "Tamba's Abacus" to teach counting to young children. Sing along with the characters or count alone (see Resources). Another website, Online Calculator, has a simple and colorful abacus that children can move the beads around electronically (see Resources). This website is well suited for children who do not have an abacus to use.