Fraction Puzzles

Grade Level: Second/Third

Math Engagement: Fractions

Materials needed: Grid sheets (8X8, 10X10, 12X12), color pencils

Specific Emphasis: Splitting objects into equal parts to demonstrate a fraction of a whole

(1)This generative activity is to find all the different ways a square can be divided up into fourths. Students in a group are given a sheet with square grids and instructed to divide the squares into four shapes, four "funky" shapes, and to prove that they are four equal shapes. This is proven by counting the individual squares in the shape. (2)The class discussion begins with a drawing of a pizza on a chalk board. The students are shown how it is divided into equal parts and what each part is called as it is eaten. For example, a pizza divided into 4 equal slices still makes one whole pizza but when one piece is eaten that piece became a fourth of the pizza and three fourths of the pizza is left. The pizza drawing is divided up into other fractional parts such as thirds, fifths. sixths and so on to demonstrate the different fractional parts of the whole. (6)The class will be structured by the introduction using the pizza followed by the showing an example of one of the grids(the example grid will be of a different size). The children will then split up into groups and be given the grid sheets. (15) The students will be instructed not to make easy equal "block" shapes but to be as creative as possible with their shapes. Close to the end of the class period the class will discuss how their groups divided up each grid and then be asked to prove their methods. The "funkiest" shapes will be posted and analyzed. (8)The main theme or big idea discussed will be the division of a whole into smaller parts to make fractions of that whole. It will also be to demonstrate the fractional parts of numbers. (10) The students will use the grid sheets and pencils to "think" and count with. It will be suggested to use a regular pencil to outline the shapes initially and then to fill in the shapes with the colored pencils. (13) Different sized and dimensioned shapes could be given for other activities to follow. Actual food such as a pizza or a pie could be brought in and divided up to show different fractional parts as well.

In my analysis of this activity, I tested two students to get an honest reaction to the credibility of the activity. The first was a first grade student at Buda Elementary. I picked this student because of her high level of achievement in the class. I have included her shape drawings. It was pretty obvious from the start that the whole concept of fractions was a little over her head. I basically had to walk her through drawing the first shape. I modeled what I was doing in creating the first shape and then instructed her to make the other three shapes. She was very interested and wanted to come up with different shapes. I kept stressing

that the shapes had to be equal and that she needed to plan out her shapes to make sure they were equal. I think she was more interested in the shapes than the fact that they were a fraction of the whole grid! She did say she understood the fact that they were a part of the whole and that they were smaller than the whole. This was encouraging even though I'm not sure I believed her.

The second student that I tested was a second grader at Kyle Elementary. He is one of the highest math students in the class. I had a lot of fun with him. I started in with the pizza example and we talked about how when you take one piece of the pizza away you will have three fourths left (if it's divided up into fourths). He didn't have a problem with that concept. He actually gave me some other examples like if it was divided up into five pieces and you took one piece away you would have four fifths left. I showed him the other students example and explained the directions. He asked a few questions along the way. For example, he asked how would you know how many squares to have in each shape. They haven't studied division or multiplication yet so it was a little hard explaining that one. I told him that I knew, because I had counted the squares, that there were 64 squares in the grid that I had given him. I also told him, to save time, that I knew each shape had to have sixteen squares because that way each shape would have the same amount and be of equal size. I did explain that it would be a different number if the grid had a different number of squares. He seemed to understand this. As he counted his squares, we talked about how you could even divide an individual square into smaller parts as long as you divided up another square the same way. He understood how you would divide up two squares into thirds and only use two from one square and one from another to make a whole square. I included his drawings to demonstrate his use of creative divisions to develop odd shapes. We had fun counting the squares, and his division of the squares, to make sure we had equal parts in each shape. He really seemed to enjoy the activity and I feel he understood the very basic concept of fractions, even though he had never been introduced to them before. He asked me to come test other projects that I had because he liked learning and helping me at the same time!

The following grids are examples of different shapes that could possibly evolve during the activity.


(3)(4)(5)



8X8 Grid




10X10 Grid








12X12 Grid




Examples of Student Work

(14)

These images were not scanned in color so much of the students' work is not clearly visible.