Odds and Evens
Are there an even or odd number of circles here:
O O O O O
How do you know?
There are 5 circles. Five is an odd number. You know because if you pair up the circles, there is a circle without a partner.
7 + 4
11
8 - 3
5
Ms. Wallace made donuts for her class. She made 9 donuts on Monday and 6 donuts on Tuesday. How many donuts did Ms. Wallace make in all? Please write the equation and answer that represents the problem.
9 + 6 = 15
Is 8 an even or an odd number? How do you know?
8 is an even number because if you have eight objects, you can pair them together without one left over.
23 + 15
38
18 - 6
12
Ms. Trent and Ms. Hickson are playing soccer. Ms. Trent scored 12 goals. Ms. Hickson scored 9 goals. How many more goals did Ms. Trent score than Ms. Hickson? Please write the equation and answer that represents this problem.
12 - 9 = 3
Is 15 an even or an odd number? Explain your thinking.
15 is an odd number. With a two-digit number you use the number in the ones place (5) to decide if a number is even or odd.
The missing number is 13.
8 - _____ = 2
The missing number is 6
Mr. Allen had some Pokemon cards. Mr. Lin gave him 24 more Pokemon cards. Now Mr. Allen has 45 Pokemon cards. How many Pokemon cards did Mr. Allen have at the beginning?
____ + 24 = 45 therefore to find the answer we take the sum 45 - 24 to find the other part.
45- 24 = 21
Mr. Allen had 21 Pokemon cards in the beginning.
Is 30 an even or an odd number? Explain your answer.
Numbers that end in zero are even numbers. If you were to pair 30 blocks, each would have a partner with none left over.
____ + 8 = 9 + 4
The missing number is 5
15 - ______ = 8 - 6
Since 8-6 equals 2, the missing number is 13 since 15 - 13 equals 2.
Ms. Wilson has a collection of snowglobes. She gave 17 snowglobes to her students. Now, Ms. Wilson has 51 snowglobes. How many snowglobes did Ms. Wilson have in the beginning?
______ - 17 = 51 therefore
51 + 17 will find the whole number at the beginning of the equation.
51 + 17 = 68 so Ms. Wilson had 68 snowglobes in the beginning.
Ms. Wilson says the number of X's below are an odd number. Do you agree. Yes or No? Explain your thinking.
X X X X X X X X X X
There are 10 X's. There is a zero in the ones place. Since zero is an even number, Ms. Wilson is incorrect.
14 - 2 = 3 + _____
Since 14 - 2 equals 12, the equation must be 3 + 9 for both sides to be equal.
2 + 7 = 10 - ____
2 + 7 = 9 so the missing number is 1 since 10 - 1 also equals 9
Mr. Lin loves to exercise. Mr. Lin did 61 jumping jacks. Ms. Callender did 38 jumping jacks. How many more jumping jacks did Mr. Lin complete than Ms. Callender? Write an equation and answer to this problem.
61 - 38 = 23
Mr. Lin completed 23 more jumping jacks than Ms. Callender.