WHOA!Yay! Math!
Tuesday Announcements!
Math joke of the day:
What do you call a group of friends who like math? Algebros !
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WHOA!Yay! Math!
Wednesday Announcements!
Math joke of the day:
If I have 4 oranges in one hand and 3 oranges in one, what would I have? Really big hands !
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SESSION 2
Develop
Using Strategies to Subtract
Learning Targets
LESSON 5 • Subtract Whole Numbers
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Start
Which One Doesn’t Belong?
A
382 – 153
B
564 – 132
C
724 – 396
D
938 – 75
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Make sense of the problem
Athletes are training for a para athletic competition. There are 2,153 athletes training for the high jump event. There are 4,002 athletes training for the cycling event.
75
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Make sense of the problem
Athletes are training for a para athletic competition. There are 2,153 athletes training for the high jump event. There are 4,002 athletes training for the cycling event. How many more athletes are training for cycling than for high jump? Use any strategy to subtract.
75
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Compare class strategies
Athletes are training for a para athletic competition. There are 2,153 athletes training for the high jump event. There are 4,002 athletes training for the cycling event. How many more athletes are training for cycling than for high jump? Use any strategy to subtract.
75
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Compare strategies
You can use place value to find 4,002 – 2,153.
You cannot subtract 3 from 2. So, you need to regroup.
Write 4,002 in a place-value chart.
There are zeros in the tens and hundreds places. So you cannot regroup the tens or hundreds yet.
Start by regrouping the thousands place.
Keep regrouping until you can subtract.
76
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Compare strategies
You can use place value to find 4,002 – 2,153.
4 thousands = 3 thousands + 10 hundreds
10 hundreds = 9 hundreds + 10 tens
10 tens = 9 tens + 10 ones
76
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Compare strategies
You can use place value to find 4,002 – 2,153.
Now you can subtract.
76
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Make connections and explain your thinking
How is regrouping thousands shown in the problem above?
Why is the 10 crossed out in the hundreds column?
Explain the regrouping shown in the tens column.
Why are 12 ones shown in the ones column?
77
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Make connections and explain your thinking
Explain how to subtract two four-digit numbers if you need to regroup in all places.
77
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Reflect on what you have learned
Look back at your Try It, strategies by classmates, Model It, and the subtraction problem in Connect It on this page. Which models or strategies do you like best for subtracting four-digit numbers? Explain.
77
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Apply your thinking to new problem
Find the difference 8,091 – 3,467. Show your work.
Solution
78
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Apply your thinking to new problem
There are 11,408 fans at the hockey game and 9,617 fans at the basketball game. How many more fans are at the hockey game than are at the basketball game? Show your work.
Solution
78
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Close: Exit Ticket
What is the missing digit that makes the subtraction problem correct?
3
6
7
8
78
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Practice
EXAMPLE
Ellema and her mom cross two peaks on a hike.
Hill Peak is 5,210 feet high. Sun Peak is
7,192 feet high. How much higher is
Sun Peak than Hill Peak?
Use a place-value chart.
First, regroup.
Then subtract.
Use the standard algorithm.
Sun Peak is 1,982 feet higher than Hill Peak.
79
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Practice
Subtract.
3,008
– 1,265
79
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Practice
Find the difference.
16,407
– 9,524
79
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Practice
The table shows the number of seats in two basketball arenas. How many more seats are in Arthur Arena than are in Griffin Fieldhouse?
Show your work.
Number of Seats | |
Griffin Fieldhouse | 22,826 |
Arthur Arena | 44,750 |
Solution
80
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Practice
In 2010, the ranching town of Bozeman, Montana had a population of 37,280 people.�In 1940, it had a population of 8,665 people. How many more people did Bozeman have in 2010 than it had in 1940? Show your work.
Solution
80
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Practice
Use the tiles below to find a number that makes each subtraction problem true. You may use a tile more than once.
80
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Practice
Soo wants to sell his car for $21,550. After a week, he lowers the price by $1,650. Then he lowers the price again, by $1,955, and sells the car. What is the final price of the car? Show your work.
Solution
80
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WHOA!Yay! Math!
Thursday Announcements!
Math joke of the day:
What is 3+4=? A math problem!
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Subject to CA’s Terms of Use for Teacher Toolbox Materials.