Bar Model Basics An Introduction to the Bar Model Strategy: Fractions Lyndsey Klempay Susan Kuehn www.barmodelbasics.weebly.com

Jia earned money babysitting. She spent 1/4 of the money on lunch Jia earned money babysitting. She spent 1/4 of the money on lunch. She spent 1/2 of the money on a DVD, and she saved $4. How much money did Jia spend on the DVD?

What are bar models? Bar models are visual representations of word problems. They help students describe relationships between items (variables) in a problem. Bar models are not intended as a replacement for all other important and effective problem solving approaches. Bar model drawing is a valuable tool to supplement your problem solving tool box.

Word problems require students to: read understand (translate) strategize compute check work Students learn to draw bar models first using numbers and computations they have already mastered.

Why Bar Models. Maximize student understanding Why Bar Models? *Maximize student understanding *Help students visualize complex relationships *Teach students to think analytically *Provide an important transition between concrete (actual objects) and abstract (algorithm) “Pictorial bridge to abstract thinking” *Help students organize thoughts to make the problem manageable or approachable. *Develops and transfers to algebraic thinking

Learning Model Drawing 1st Process – how to use model drawing to solve word problems. 2nd Application – apply process independently

Discrete Method Work with the discrete method of model drawing first Discrete Method Work with the discrete method of model drawing first. Draw one square to represent each object in the problem. Reinforce one-to-one correspondence. The student moves from using manipulatives to using symbols to represent the objects.

Continuous Model Students write the appropriate number inside the unit bar, instead of drawing one unit for each object. Draw a unit bar, adjust it, and add values. Most problems we will practice will use the continuous model. 4

Step-by-Step Model Drawing Char Forsten 1. Read the entire problem. 2 Step-by-Step Model Drawing Char Forsten 1. Read the entire problem. 2. Rewrite the question in sentence form, leaving a space for the answer. 3. Determine who and/or what is involved in the problem. 4. Draw the unit bar(s). *5. Chunk the problem, adjust the unit bars, and fill in the question mark. *6. Correctly compute and solve the problem. 7. Write the answer in the sentence, and make sure the answer makes sense.

I have 3 red M&M’s and 6 yellow M&M’s. How many M&M’s do I have I have 3 red M&M’s and 6 yellow M&M’s. How many M&M’s do I have? Discrete: Continuous:

I have 12 red color tiles and 14 blue color tiles I have 12 red color tiles and 14 blue color tiles. How many color tiles do I have? Discrete: Continuous:

There are 109 boys and 85 girls in the fifth grade There are 109 boys and 85 girls in the fifth grade. How many students are there? Discrete: Continuous:

Important. Follow a consistent approach. Chunk information Important *Follow a consistent approach. *Chunk information. *Provide explicit, guided instruction from the beginning. * Embed problem solving throughout all standards using ANY problem solving methods.

Let’s Try. Use your journal and manipulatives if needed Let’s Try! Use your journal and manipulatives if needed. Feel free to use colored pencils or crayons to develop your solution.

If 2/3 of a number is 4, what is the number?

Marissa spent 2/3 of her money at the mall and had $10 left Marissa spent 2/3 of her money at the mall and had $10 left. How much money did she spend at the mall?

A pie was cut into 6 equal pieces. Luke ate 1/3 of the pie A pie was cut into 6 equal pieces. Luke ate 1/3 of the pie. How many pieces were left?

There is 1/2 of a candy bar that needs to be divided evenly among 3 children. What fraction of the total candy bar will each child receive?

There was 1/2 of a chocolate cake left over after dinner There was 1/2 of a chocolate cake left over after dinner. Four people shared it equally the next day. What fraction of the whole chocolate cake did each person eat?

Terra’s monthly allowance is $48 Terra’s monthly allowance is $48. She puts 1/2 of her allowance into savings and gives 3/4 of the remaining money to a local charity. How much money does Terra have left for herself each month?

Marcus wrote 3 pages of his science report on Monday Marcus wrote 3 pages of his science report on Monday. He wrote 2/3 of the remainder on Tuesday. He still needed to write 2 more pages. How many total pages was Marcus’s science report?

Angela baked cookies. She gave 1/3 of them to her sister, and she put 5/8 of the remaining cookies in the freezer. If she had 1 dozen cookies left, how many cookies did she bake?

Kathy had fun baking lots of cookies Kathy had fun baking lots of cookies. She left them on a plate to cool while she went shopping with her dad. Her brother saw the cookies and took 1/2 of them to his Scout meeting. Her sister took 2/3 of the remaining cookies to share with her friends. Finally, her mom took 1/2 of the remaining cookies to her Book Club meeting. When Kathy and her dad got home, there were only 5 cookies left on the plate.

Danny loved candy, especially chocolate bars Danny loved candy, especially chocolate bars. He loved them more than football and his favorite cars. He loved them more than video games and the rest Of all the things he loved, chocolate was the best. For a special treat he was given a huge bar for free. It was so very big. It measured twelve squares by three. Though he loved his chocolate, he thought it was fair, If with his friends, he decided to share. Danny broke up the bar and half of it he took. He shared the other half with Ted, Joe, and Brooke. Of the half share the three friends took a third. They gobbled chocolate so fast, no one said a word. If Danny took half, how many squares did he get? This answer is easy, there’s no need to fret. His friends received 1/3 of 1/2 of the bar. So how many squares do they have so far? So here’s the big question, its answer you’ll find. What fraction of the big bar did the friends get from Danny so kind?

Jia earned money babysitting. She spent 1/4 of the money on lunch Jia earned money babysitting. She spent 1/4 of the money on lunch. She spent 1/2 of the money on a DVD, and she saved $4. How much money did Jia spend on the DVD?

1. Read the entire problem. If 2/3 of a number is 4, what is the number? Reflectively read the problem. Read the problem without reading the numbers. Visualize the problem without the numbers interfering with thoughts. Reread the problem again with the numbers.

2. Rewrite the question in sentence form, leaving a space for the answer. The number is _____ . Focus on the question to strengthen understanding of the problem and to guide thinking and modeling.

3. Determine who and/or what is involved in the problem. The number

4. Draw the unit bar(s). The number

5. Chunk the problem, adjust the unit bars, and fill in the question mark. ? The number 4

6. Correctly compute and solve the problem. Step One: 4 ÷ 2 = 6. Correctly compute and solve the problem. Step One: 4 ÷ 2 = ? Each box is 2. Step Two: 2 + 2 + 2 = ? 2 x 3 = ?

7. Write the answer in the sentence, and make sure the answer makes sense. The number is _____.

Ask students to write their own questions related to the original problem. Great homework assignment!

TIPS. Provide graph paper to help with spacing and alignment TIPS *Provide graph paper to help with spacing and alignment. *Create a daily word problem. Use strips of paper or sticky labels for the math notebook. *Use “proof” sheets or show evidence, NOT “scratch” or “scrap” paper. *Create your own problems. Change names, numbers, circumstances, or questions using previous practice problems. * Work backwards. Once students have mastered model drawing, give a solution to the class and ask them to create a story problem.

Practice makes permanent Practice makes permanent! Char Forsten Model drawing is a picture of success! Remember: Solve each problem yourself before assigning it to students. 

Great Websites Thinkingblocks Schooltube Learnzillion divide Learnzillion multiply Vimeo Mathplayground Thinkingblocks Index GreatSource Thinkingblocks Fractions TheSingaporeMaths-Great Questions        

What AKS have we covered today What AKS have we covered today? Turn and talk to your neighbor about what you think we covered today.