Find the Missing Number
Write three subtraction equations with a answer of 6.
Answers vary
These are examples of what strategy?
7-7=0 ; 12-12=0
Take All facts
Difference
Choose the correct equation to match this problem:
John's book is 18 centimeters long. The book is 9 centimeters longer than John's pencil. How long is his pencil? Which of the following represents this situation?
a) 18+9=p b) p+18=9 c) 9-p=18 d) p+9=18
p+9=18
Sara measured a poster. The first side of the poster was 81cm long. The second side was 53 cm long. How much longer was the first side than the second side of the poster?
81-53=28cm longer
Write three different addition equations for 15.
Answers vary
These are examples of what strategy?
7+0=7 ; 0+14=14
Add Zero Facts
Sum or Total
Write and solve an equation to match this problem: "The coach has 16 tennis balls and 9 ping-pong balls in a bag. How many more tennis balls than ping-pong balls are in the bag?"
Equations will vary. Examples: 16-9=7;9+7=16
Jonah loved to read. Yesterday he read for 36 pages and today he read 28. How many pages did Jonah read in all?
36+28= 64 pages
a) 9+7=10+_____
b) 18= 12+______
a) 6
b) 6
This is an example of what strategy?
12+9=__n__
= 11+10=__n___
Friendly Numbers
The property by which the sum remains unchanged no matter how the numbers being added are ordered, so that a+b=b+a
Commutative property of addition
16-8 is a Half Fact. Write two other Half Facts.
Answers will vary. Examples: 14-7; 12-6;18-9
Malcom collects special marbles. He had 3 marbles. For his birthday, Malcolm received 17 more special marbles. How many marbles does Malcolm have now?
34+17= 51 marbles
a) _____=20-11
b) 11-4=______
a) 9
b) 7
These are examples of what strategy?
7+7=14 ; 3+3=6
Doubles Facts
A number that can be exactly divided by 2, all even number end with 0,2,4,6, or 8 is what?
Even Number
Della says that 7+8 is a Doubles Plus One fact. Do you agree with Della? Why or why not?
Della is correct.
7+7 is a Doubles Fact. 7+8 is 1 more than 7+7, so it's a Doubles Plus One fact.
Rosa read 129 pages last week and 124 pages this week. Amy read 127 pages last week and 109 pages this week. Who read more pages in all during this week and last week? How many more pages did she read? Show your work with numbers, pictures, or words.
Rosa: 129+124=253
Amy: 127+109=236
253-236=17 pages; Rosa read 17 more pages than Amy.
a) 18= _____ + 6
b) 4+8+2+6=______
a) 12
b) 20
These are examples of what strategy?
10-5=5 ; 16-8=8
Take Half facts
A number that cannot be evenly divided by 2; all odd numbers end with 1,3,5,7 or 9 is what
Odd Number
Josh says that all the Doubles Facts (6+6) have even sums. Do you agree with Josh? Why or why not?
Josh is correct. If you put the same number of the top and bottom rows of the number rack, every bead has a partner, so the answer is even.
Explain how you can use a Make Ten fact to solve 9+6. Include the answer to 9+6 in your answer.
9+6 is the same as 10+5 if you take 1 away from the 6 and give it to the 9, and 10+5=15