1. Lesson 17
NYS COMMON CORE MATHEMATICS CURRICULUM
6•2
Lesson 17:Divisibility Tests for 3 and 9
Classwork
Opening Exercise
Below is a list of
numbers. Place each number in the circle(s) that is a factor of the number. You will place some
numbers more than once. For example if
were on the list, you would place it in the circles with , , and because
they are all factors of .
;
;
2
;
;
;
;
;
;
;
5
4
8
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Divisibility Tests for 3 and 9
1/13/14
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2. Lesson 17
NYS COMMON CORE MATHEMATICS CURRICULUM
6•2
Discussion

Divisibility rule for :

Divisibility rule for :

Divisibility rules for :

Divisibility rule for :

Divisibility rule for
:
Example 1
This example will show you how to apply the two new divisibility rules we just discussed.
Is
divisible by
or ? Why or why not?
a.
What are the three digits in the number
b.
What is the sum of the three digits?
c.
Is
d.
Is the entire number
e.
Is the number
?
divisible by ?
divisible by ? Why or why not?
divisible by ? Why or why not?
Lesson 17:
Date:
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Divisibility Tests for 3 and 9
1/13/14
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3. NYS COMMON CORE MATHEMATICS CURRICULUM
Lesson 17
6•2
Example 2
Is
divisible by
or ? Why or why not?
Exercises
Circle ALL the numbers that are factors of the given number. Complete any necessary work in the space provided.
1.
Is
divisible by
Explain your reasoning for your choices.
2.
Is
divisible by
Explain your reasoning for your choices.
Lesson 17:
Date:
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Divisibility Tests for 3 and 9
1/13/14
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4. NYS COMMON CORE MATHEMATICS CURRICULUM
3.
Is
Lesson 17
6•2
divisible by
Explain your reasoning for your choices.
4.
Is
divisible by
Explain your reasoning for your choices.
5.
Is
divisible by
Explain your reasoning for your choices.
Lesson 17:
Date:
©2013CommonCore,Inc. Some rights reserved.commoncore.org
Divisibility Tests for 3 and 9
1/13/14
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5. Lesson 17
NYS COMMON CORE MATHEMATICS CURRICULUM
6•2
Lesson Summary
To determine if a number is divisible by
or :

Calculate the sum of the digits.

If the sum of the digits is divisible by , the entire number is divisible by .

If the sum of the digits is divisible by , the entire number is divisible by .
Note: If a number is divisible by , the number is also divisible by .
Problem Set
1.
Is
divisible by both
and ? Why or why not?
2.
Circle all the factors of
from the list below.
3.
Circle all the factors of
from the list below.
4.
Write a digit number that is divisible by both
and .
and . Explain how you know this number is divisible by
5.
Write a digit number that is divisible by both
and .
and . Explain how you know this number is divisible by
Lesson 17:
Date:
©2013CommonCore,Inc. Some rights reserved.commoncore.org
Divisibility Tests for 3 and 9
1/13/14
S.73
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Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
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