Extra
What is one strategy you can use to decide if a number is an even number?
1. See if the objects can be separated into two equal groups.
2. See if the number ends in 0, 2, 4, 6, 8
3. See if objects can be paired with out any left overs
What is the answer to this word problem? Samuel saw 4 dogs in his backyard. Each dog has 4 legs. How many legs do the dogs have all together?
*Complete Sentence - every person in your group must write it on the whiteboard
There are 16 dog legs in all.
What are the missing numbers.
Skip count by 2's.
32,34, 36, ____, ____
38, 40
What is the number sentence for this array?
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&&&&&
5 + 5 = 10
OR
2 + 2 + 2 + 2 + 2 = 10
Is the number of items even or odd?
9
Show how you solved on your whiteboard.
Odd - answers may vary
What is a strategy you can use to decide if a number is an odd number?
1. See if the object can separate into two equal groups with two equal addends (ex: 2 + 2). If not, the number is odd.
2. See if objects can be paired - if there are any left over, the numbers odd.
3. Does the number end in 1, 3, 5, 7, 9
What is the answer to this word problem? Cierra has 3 piles of books. Each pile has 5 books. How many books does Cierra have?
Write a complete sentence on your whiteboard.
Cierra has 15 books.
Skip count by 3's. What are the missing numbers?
12, 15, 18, 21, ___, ____, ____
24, 27, 30
What is the number sentence for this array?
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#####
#####
5 + 5 + 5 = 15
OR
3 + 3 + 3 + 3 + 3 = 15
Is the number of items even or odd?
10
Show how you solved on your whiteboard
Even - answers may vary
Give 2 examples of arrays you see around the classroom.
Answers may vary
Mrs. Sandford wanted to arrange the desks into 4 rows of 5. If Mrs. Sandford has 22 students, will she have enough desks?
Yes/No Because...
She will not have enough because 4 rows of 5 makes only 20 total.
Skip Count by 4's. What are the missing numbers?
8, 12, ____, 20, ____, 28
16, 24
What is the number sentence for this array? &&&&&&&&&&
&&&&&&&&&&
&&&&&&&&&&
10 + 10 + 10 = 30
OR
3 + 3 + 3 + 3 + 3 + 3 + 3 + 3 + 3 + 3 = 30
Is the number of items even or odd?
19
Show how you solved on your whiteboard
Odd - answers may vary
Give 3 examples of arrays you see around the classroom
Answers may vary
Julian has 12 toy cars. What are TWO different ways he could create an array with his toy cars?
Show on your write board AND write a repeated addition sentence/equation that matches
1 row of 12, 12 rows of 1, 12 columns with 1 row, 1 column with 12 rows, 2 rows with 6 columns, 6 rows with 2 columns, 4 rows with 3 columns, 3 rows with 4 columns
What is the pattern?
6, 12, 18, 24, 30
Skip counting by 6
What is the number sentence for this array?
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@@
@@
4 + 4 = 8
OR
2 + 2 + 2 + 2 = 8
Ava said the number 14 is even because if she paired 14 objects, there are none left over. Is she correct?
Jordan said 14 is even because he could separate 14 items into two equal groups with 7 items in each group.
Who is correct?
They are both correct because you could use either way to figure out of a number is even.
Name an example of an array you see in the classroom, write a repeated addition sentence that matches, AND give the total number of items in the array.
Answers will vary
A 2nd Grade class planted their beans this week. They arranged their cups into an array. If there are 24 students in the class, how could they have arranged the cups?
Complete Sentence
Draw your array
Write both repeated addition sentences that match
Answers may vary, example below:
They could have arranged the cups into 2 rows and 12 columns (2 rows of 12).
XXXXXXXXXXXX
XXXXXXXXXXXX
12 + 12 = 24 or
2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 = 24
What is the pattern?
25, 30, 35, 40, 45, 50
*How can we use skip-counting by 5 other ways in math?
Skip counting by 5's
*Telling Time, Money, etc.
What is the number sentence for this array?
XXXX
XXXX
XXXX
XXXX
4 + 4 + 4 + 4 = 16
Richard says the ONLY way to tell whether a number is even or odd is to look in the ones place.
Is he correct? Why or why not?
He is not correct. You can use that to check if a number is even or odd, but that is NOT the only way.