Division, map reference frames, and measures of angles
6.1 multiplication and division number stories
Often times when we solve real-world puzzles, the problem is not just given to us. We have to read through or even sometimes find out information, determine which pieces of information are important and which are not, and then create our own number sentence problem that we can then solve. Number stories help us to accept challenges and also help us to persevere and use both logic and creative ability. After all, it feels good to face a challenge and have success when we complete it! It makes a boring day interesting and a good challenge can even revitalize all your senses.
PUZZLE: There are 28 chairs in the classroom and 4 rows of chairs. How many chairs are in each row?
Step 1: We want to know how many chairs are in each row. We will use the letter "c" to represent this unknown. Step 2: We need to use the fact that there are 28 total chairs and 4 rows of chairs to solve this problem. Step 3: We can use division to find the answer. 28 chairs must be divided equally by 4 rows. The number model for this would look like 28 ÷ 4 = c Step 4: 28 ÷ 4 = 7 Step 5: Answer: There are 7 chairs in each row. 28 ÷ 4 = 7 |
- Grand Slam Baseball: Solve these number stories and hit a home run!
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6.2 strategies for division
The Hiawatha 4th graders decided to have a fundraiser to raise money for the Capital Area Humane Society. They ordered a bunch of chocolates, packaged them up into boxes, and sold them. On the last day of the fundraiser they had 189 chocolate candies left, but they were not sure if they had enough boxes. Each box held 21 chocolate candies. How many boxes did they need?
What division strategy can you use to solve this problem? |
Multiplication / Division Diagram
"What number times 21 equals 189?" or "189 divided by what number equals 21?" b x 21 = 189 or 189 / b = 21 Use Manipulatives Since we don't actually have 189 chocolates to put 21 into as many boxes as possible, we can use something else to stand in for our chocolates... like counting cubes. If we take 189 and divide them up into groups of 21, we get 9! Draw a Picture It can be very helpful to visualize a problem in order to more easily figure out how to solve it. Using paper and pencil, we can draw the189 candies, and then divide them up into 21 candies per box. When we are done, we can just count the boxes. Use Smaller "Friendly Numbers" I know that 20 x 5 is 100, so then 21 x 5 is just 5 more so it is 105. I also know that 20 x 10 is 200 so the number of boxes must be between 5 and 10. So If I take my 5 x 21 and + 21 + 21 + 21 + 21 I will get 189. That is a total of 9 boxes. Using Multiples If we simply count the number of 21s it takes to reach our total, we can figure out how many boxes we would need. This can easily be done using multiples. |
20 x 5 = 100 + (1 x 5) = 105
105 + 21 = 126 126 + 21 = 147 147 + 21 = 168 168 + 21 = 189 |
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- Visit the City of Murb: Navigate your Murbian through the city using math! (Choose the ÷ symbols)
- Division Games: There are A TON of division games here to practice your division and fact families. |
6.3 the partial quotients division algorithm - part 1
In order to be able to do harder division problems, we need to review what the names of each part of a division problem are called.
Remember... The dividend - the number that is being divided - is 35 The divisor - the number that the dividend is being divided by - is 5 The quotient - the answer to the problem - is 7 |
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- The Quotient Cafe: Help the customers divide the food evenly among themselves.
- Review It: Watch as 94 ÷ 6 is solved using the partial-quotients algorithm! - Review It: Watch as 371 ÷ 4 is solved using the partial-quotients algorithm! |
6.4 expressing and interpreting remainders
- Time for Remainders: Help the math tutors solve these word problems and save the day!
- Practice Problems: Can you solve all these practice problems of division story problems? - We Built This City: Can you figure out what to do with the remainders and build the city? |
6.5 rotations and angles
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- Alien and Angles: Protect the planet and rescue the Aliens!
- Supersoaker Water Fight: How many things can you get wet using angles and your supersoaker? - Hit the Target: Have you ever noticed all the different angles in sports like soccer and tennis? |
6.6 using a full circle protractor
- Kung Fu Angles: Help the White Nija become a master of angles.
- Go Bananas: The monkey has lost his bananas. Help him get them back! |
6.7 the half circle protractor
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- Measure It: How accurately can you measure these angles?
- Name That Angle: Use the protractor to measure the angle. - What's My Angle: Use the protractor to measure the angle. - Playing with Protractors: Use this online half protractor to measure and create different angles. |
6.8 rectangular coordinate grids for maps
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When Mr. C visited South Africa, he went on a safari at a game park.
A game park is a protected area of land where wild animals can live safe from being hunted. When the safari started, Mr. C was really excited to see the giraffes. The guide explained that since the animals move all around the park, it can be difficult to know exactly where they are. Mr. C got worried. How were they ever going to find the giraffes? It was a really big park! The guide told him not to worry because they used math to solve the problem! The guide pulled out a map of the park and showed Mr. C how they had divided it into smaller sections using a grid and labeled each axis with numbers starting with 0 at the origin. This way, they could track and record the locations of the different animals at different points in the day and look for patterns. The guide said that around noon the giraffes generally head over to the point (8,6) because there are acacia leaves there - which is a giraffes favorite snack! |
- Find the Aliens: Use the coordinate plane to identify the location of all the different aliens.
- Stock the Shelves: Put the groceries back where they belong before time runs out! - Jeopardy: "I'll take coordinates for 300 please!" Answer the questions and earn points! |
6.9 global coordinate grid system
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absolute location: the exact location of a point on the Earth by using a grid system. Equator: an imaginary line that divides the Earth into Northern and Southern hemispheres. Prime Meridian: an imaginary line that divides the Earth into Western and Eastern hemispheres. hemisphere: a region created when the Earth is divided in half. |
- US Latitude and Longitude: Can you name the city using the given latitude and longitude?
- Treasure Hunt: "Argh me matey! Can ye help this ol' pirate find me treasure?" |
6.10 the partial quotient division algorithm - part 2 / U.S. Traditional Method
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- Snork’s Game: Can you help the lovable monster named Snork learn how to do long division?
- Who Wants To Be A Hundredaire: Is that your final answer? Get them right and you could win big! - Tic Tac Toe: Use your knowledge of division to get three in a row! Can you win the day? |
"Show what you know"
are you ready?
Can YOU find the answer to division story problems?
There are 45 cookies in a box. James and his 4 friends want to share them equally. How many whole cookies will each person get?
- Number model with unknown: _______________________
- Answer: ________ cookies
- Summary number model: ____________________________
- Number model with unknown: _______________________
- Answer: ________ brownies
- Summary number model: ____________________________
- 55 ÷ 6 Answer: ____________
- 141 ÷ 7 Answer: ____________
Can YOU choose between two payment plans and decide which is cheaper?
Mr. Monk wants to buy a stove and pay for it in 1 year. L-Mart offers two plans, and he wants to choose the cheaper one.
- Plan A: $8 each week; a total of 47 payments
- Plan B: $32 each month; a total of 12 payments
- Which plan would cost less? ______________________ Explain your answer.
Can YOU measure angles in degrees using a protractor and decided which type of angle it is?
Can YOU plot and label points on a coordinate grid ?
Can YOU insert parentheses to make a number sentence true?
Can YOU round numbers to the nearest ten thousand?
Can YOU measure reflex angles using a protractor ?
- 4 + 7 * 2 - 1 = 21
- 7 + 2 * 5 + 2 + 8 = 29
- 13 - 1 * 6 + 2 = 25 - 4 * 5
Can YOU round numbers to the nearest ten thousand?
- 21,521
- 14,369,874
- 245,967,391
Can YOU measure reflex angles using a protractor ?
Can YOU draw reflex angle ABC so that it measures 219 degrees?
Can YOU divide two numbers and express the remainders as fractions?
Can YOU divide two numbers and express the remainders as fractions?
- 124 ÷ 18 Answer: ____________
- 546 ÷ 23 Answer: ____________