Bring to class three various-sized pumpkins from a farmer's market or the grocery store near Halloween. Allow the students in the class to view and feel each of the pumpkins. Have each student write his own estimation of how many pumpkin seeds are in each of the pumpkins. Use a sharp knife and instruct students to stand back, then carve the top out of the pumpkin. Allow each student to peer inside and decide whether he'd like to keep his estimation guesses or modify them. Ask the class to help count the pumpkin seeds in each pumpkin. The students with the closest estimations win prizes.
Write a few typical Halloween items on slips of paper and challenge students to guess what they are by describing them using only mathematical terms. For example, an pumpkin is asymmetrical, somewhat spherical and contains visible vertical line segments. A piece of candy corn contains three horizontal sectors and appears as an isosceles triangle. Divide the classroom into teams for guessing the riddle answers and keep score to create a Halloween guessing game with math riddles.
Give each student a large handful of candy corns and instruct them to use the candy pieces to configure verbal word problems you provide. The game reinforces listening skills while practicing basic computations. For example, instruct the students to set aside a pile of five candy corns, add five, subtract three, add two more and subtract six. Each child should be left with a pile of three candies in her pile. Challenge the students by using two-digit numbers and speaking the operations quickly. Keep score by dividing the class into two teams and giving each team a point for each student who successfully completes the verbal equations.
Create a matching game by devising Halloween-related math word problems, cutting them out and pasting them onto blank note cards or pieces of black construction paper. On another set of cards or orange-colored paper squares, write the answers to the word problems. Each student may play the matching game by choosing one black paper, solving the problem and turning over one orange paper to see if he found the matching answer. Each child takes turns until all problems have been solved and matched with their correct answers.