Fractions Can Be Fun
Lesson 1 of 10
Objective: SWBAT identify and talk about fractions of halves, thirds and fourths of a whole.
Warming Up Our Fractions
Students will begin today with small (6 inch) colored paper squares and circles. I ask them to pick up one square and fold it in half. How many pieces do you have? (2). When I break something in half, how many pieces do I get? (2) Can anyone come up and write one half on the board? (I ask for a student to come up and write 1/2. As a class we discuss if that is correct. I then do any correcting necessary and then ask the students to label each part of their square as 1/2
I ask students to pick up another square and fold it in half and in half again. Now open it up. How many pieces do you have now? (4). Does anyone know what it is called when we break something into 4 pieces? (quarters). Does that remind you of anything like in money.. or shapes (quarters and quadrilaterals). Can anyone write 1/4 for us? (A volunteer comes up to write 1/4). Great now will you label each part 1/4.
Can you take another square and make it into thirds? Can anyone think of how we might do that? (I let 1 -2 people try to explain/demonstrate thirds and if no one can do it, I show the group how to fold a paper into thirds.) How many pieces do we have? (3). Can anyone write 1/3? (I have a volunteer writhe 1/3 on the board.) Now will you label each piece with 1/3.
Now I would like each of you to take a pair of scissors and cut off 1/2 from the paper folded in half. (give them a few minutes to do this), now cut 1/4 from the square labeled in quarters. Now cut 1/3 from the paper labeled thirds.
Use those pieces to tell me which is the biggest (raise your hand) 1/2 or 1/4. Look at the number on the bottom of the fraction. Which number is bigger? Why do you think that the number is bigger but the piece is smaller? (I let students try to explain this and then I build upon what they have said to introduce the idea that the more pieces we cut something into - which is what the bottom number - denominator- stands for, the smaller the pieces so a big number means many pieces.)
I do a similar thing with the 1/2 and the 1/3.
Fractions of a Pile
I ask students to put their cut outs at the top corner of their desk where they can see them. Now I tell them that I am going to hand them a tower of 12 snap blocks. When they get their tower, they should make piles for each color they have.
I hold up my tower after theirs are sorted. OK I have twelve blocks in all, do you? So when I talk about each color, I am going to put a 12 on the bottom (denominator) of my fraction like so. (I write a fraction with twelve on the bottom on the board.) Now I have 3 green so I know that 3 out of 12 are green so my fraction is 3 out of 12 or 3/12ths. Look at your green, can you write a fraction on the paper on your desk, putting 12 on the bottom and how many green on the top. (I look around as students are writing.) Good how many had 1/12 that were green? How about 2/12?
Let's look at my blue cubes. How many do I have. I count 1 -2-3-4 -5. Ok I have 5 blue out of how many in all? We recount the 12 including the blue as this is a common mistake students make in leaving out the ones they are referring to. OK so I am going to write 5 out of 12 or 5/12.
Great can you write down a fraction of your blue squares out of how many you have in all. Remember that 12 goes on the bottom because we all have 12. Great. How many had 3/12s blue? How about 7/12s?
Do you think you can write down the fraction for how many yellow cubes you have? Remember what number goes on the bottom? How many do we have in all? Right 12 goes on the bottom. Can you write your number on the top? Who can hold up their tower and tell us their fraction? I let 3 or 4 students share their fractions.
Excellent, you are all making fractions. We are going to do a project today writing fractions for things we sort. I would like you all to come to the rug and place your cubes in the bucket as you come up. Let's see if you can all be here by the time I count from 25 to 0.
I explain to students that they will be working in small groups to explore fractions.
In group one students will sort fractional pictures into halves, quarters and thirds.
The next group will take 16 colored chips and then sort them into piles by color and fill in the fractions of each color that they have. They can repeat the process with 8 chips if they have time.
The third group will use the IPAD to practice identifying fractions with the Pizza Man App
To close today, I ask students to return to their seats after they clean up the area they are working at. I ask them to draw a rectangle in their math journal. Now I ask students to draw a line to show half of the rectangle. Can they draw another line to show quarters? Can they label the quarters in their drawings.
I ask them to draw a second rectangle and divide it into thirds and color one third. Can they label the sections as thirds?
This allows me to quickly check to see if students are gaining an understanding of quarters, thirds and halves.