Read Ten Little Fish to your students. It counts down from ten to one. Have students place their ten Goldfish in front of them. Then, have your students act out the story as it happens. Have them take away a Goldfish as one swims away.
After you finish reading the story, have your students gather their ten Goldfish. Ask them to pull out one cracker and then ask to put one more with that. Ask them how many they have total. They should be able to easily answer two. Continue with different addition problems, such as two plus three, four plus four, and so on.
When you have finished with addition, move on to subtraction. Have your students gather their ten Goldfish again, then have them take four away. Ask them how many are left. Continue with different subtraction problems, such as seven take away three, five take away one, three take away two, and so on.
After you have finished adding and subtracting, let your students eat the Goldfish.