Download Chapter 2 Enrichment

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CH
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APTER
2
Estimation and Number Theory
PROBLEM SOLVING
Thinking Skills
1.
I am a factor of 50 and a multiple of 5.
I am a 2-digit number greater than 10 but less than 40.
What number am I?
2.
Ms. Atkinson estimates a total cost of $90 for her grocery bill. If she rounds
the cost of each item on her grocery bill to the nearest ten dollars, what is
the least possible price Ms. Atkinson will pay for the fish?
Items
8
Cost ($)
Muffins
18
Milk
12
Meat
25
Fish
?
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Solve. Show your work.
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Solve.
3.
Find the sum of all the factors of 48 and the sum of all the factors of 64.
Then find the difference between the two sums.
4.
Two factors of 32 are x and y. The sum of x and y is 12.
The smaller of the two numbers is x. Find the value of x and y.
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PROBLEM SOLVING
Strategies
5.
Ms. Duff wants to give her students some apples.
If she gives each student 7 apples, there will be no apples left.
If she gives each student 4 apples, there will be 18 apples left.
How many students are in Ms. Duff’s class?
6.
Which number does not belong in the group? Color it.
Explain your answer.
72
54
24
18
49
27
10
36
15
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Answer the questions.
Chapter 2 Estimation and Number Theory
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Solve.
7.
These numbers are multiples of two numbers. Rewrite them into two sets
of five multiples. Some numbers will be used in both sets of multiples.
64 16 27 18 24 48 9 32
Numbers
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8.
Multiples
Ricky works part-time at a store every 2 days.
Anwar also works part-time at the same store every 3 days.
They first met at the store on a Monday.
On which day will they meet for
a. the second time?
b.
the third time?
Enrichment 4A
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PROBLEM SOLVING
Exploration
Solve.
10.
12
Make a list of the first nine multiples of 9.
Then multiply 9 by consecutive whole numbers to show how to find
the multiples. Lastly divide the multiples by the same consecutive
whole numbers to get a quotient of 9.
The first one has been done for you.
Multiples of 9
Multiply
Divide
9
1⫻9⫽9
9⫼1⫽9
What do you notice in the second and third columns?
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9.
Chapter 2 Estimation and Number Theory
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Answer the question.
11.
Estimate the sum and the difference of 7,309 and 2,876 using two estimation
methods. Which method gives you the more accurate answers?
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Method 1
Method 2
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Journal Writing
Solve.
12.
Clark estimates the sum of two numbers using two methods.
Write the steps used in each method.
Name each method used.
a.
Method 1
4,728 ⫹ 1,095 ⫽ ?
Estimated sum is 5,000.
Step 1
b.
Method 2
4,728 ⫹ 1,095 ⫽ ?
Estimated sum is 5,800.
Step 1
Step 2
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Step 2
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13.
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Jack, Keith, and Lee completed these estimation problems. Find the errors.
a.
Estimate the product of 247 and 3 by rounding to the nearest hundred.
Jack
247 ⫻ 3 ⫽ ?
300 ⫻ 3 ⫽ 900
Error:
b.
Estimate the quotient of 95 and 4.
Keith 95 ⫼ 4 ⫽ ?
80 ⫼ 4 ⫽ 20
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Error:
c.
Estimate the quotient of 73 and 3.
Lee
73 ⫼ 3 ⫽ ?
90 ⫼ 3 ⫽ 30
Error:
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