Milk Carton Computer

This activity will teach children/students how to create a Milk Carton Computer they can use to help them with their math homework.

Start by cleaning out and drying off a 2L milk carton. Position the milk carton so that one of the triangular peaks at the top is facing towards you.

Next, help your child/student cut two rectangular openings into the side of the box that is facing you. The openings should be about 3 centimetres high by 8 centimetres wide. Cut one opening about 2 centimetres from the top of the carton face, and cut the second opening about 2 centimetres from the bottom of the carton face.

Next, cut a piece of cardboard so that it is 8 centimetres wide by 23 centimetres long. Push the piece of cardboard in through the top opening of the milk carton, and out through the bottom opening. Use tape to attach the piece of cardboard at the top edge of the opening. The excess cardboard coming through the bottom end of the carton can hang free or the student can choose to fold this and tuck it under the carton.

Have the child decorate their Milk Carton Computer using wrapping paper, sparkles, and stickers. As an example, they could make their own computer, decorate it to look like a little boy and call it “ComPETER” or a little girl and call it “ComKaren”.

Before the students can start computing they will have to create the Magic Cards that go along with the computer. To do so, they will need to make 63 cards that are about 6 centimetres in length and 6 centimetres in width out of cardboard. You can also buy index cards from the dollar store but be sure to choose a size that will fit inside the rectangular openings in the milk carton.

Have the child finish the cards by using the following number combinations. Have them write the first number of the combination on the front of the card, and the second number of the combination on the back of the card.

(0,1) (0,2) (0,3) (0,4) (0,5) (0,6) (0,7) (0,8) (0,9)
(1,1) (1,2) (1,3) (1,4) (1,5) (1,6) (1,7) (1,8) (1,9)
(2,2) (2,3) (2,4) (2,5) (2,6) (2,7) (2,8) (3,3) (3,4)
(3,5) (3,6) (3,7) (4,4) (4,5) (5,5) (5,6) (5,7) (5,8)
(5,9) (6,5) (6,6) (6,7) (6,8) (6,9) (7,4) (7,5) (7,6)
(7,7) (7,8) (7,9) (8,3) (8,4) (8,5) (8,6) (8,7) (8,8)
(8,9) (9,2) (9,3) (9,4) (9,5) (9,6) (9,7) (9,8) (9,9)

Now the students can use their Milk Carton Computer. Have them choose a Magic Card. The student will read the number on the front of the card (i.e. 9) and count out that many objects from a pile of beans or beads. Next, they insert the card into the top opening of the Milk Carton Computer so that the number that was counted out is facing up. When it comes out the bottom opening, the number on the other side of the card will be facing up. The child will then have to create that second number, either by adding or subtracting objects to their original pile of beans or beads. For example, if the number 5 showed up, they would subtract 4 objects from their original pile of 9 to leave them with 5 beans or beads.

Students can use this Milk Carton Computer to help with their understanding of addition and subtraction.

This activity will reinforce the child’s understanding of counting strategies and simple tallies.