2.NBT.5 Place Value Addition and Subtraction Feel free to do 1 or a couple of slides per day and then add your own.

Add Mentally Be ready to explain how you thought about your answer 13 + 8 Student 1 Decomposing 10 + 8 = 18 and then I counted up 3 = 21 Student 2 Making ten and then counting up 13 + 7 = 20 Plus one more left over from the 8 = 21 Students may think of more ways

Add Mentally 14 + 15 Student 1 Adding tens and ones 10 + 10 + 9 = 29 Student 2 Creating easier sums Doubles 15 + 15 = 30 so 14 + 15 = 29 Other ways are possible

Add Mentally 26 + 24 Student 1 Making ten 20 + 20 + 10 (6+4) = 50 Student 2 Doubles or thinking of money I know 25 + 25 = 50 26 has 1 over 25 and 24 has one less so they both equal 25

Add Mentally 17 + 12 + 24 Student 1 example 10 + 10 + 20 = 40 7 + 6 (2+4) = I know 7 plus 7 is 14 so 7 + 6 is 13 40 + 13 = 53

Add Mentally 67 + 28

My friend added mentally and showed their work below My friend added mentally and showed their work below. Is my friend correct? 67 + 18 First I added 60 + 10 and got 70 Then I added 8 Plus 2 to get 10 Then I added 5 more So, my total is 75

True or False Discuss with a partner 14 + 36 = 34 + 16

Subtract Mentally 37 – 18 Student 1 Making 10’s 37 – 10 = 27 27 – 7 = 20 20 – 1 = 19 Student 2 Counting / Number line 18 + 10 = 28 28 + 10 is 28 which is 1 too many so 28 + 9 10 + 9 jumps on a number line = 19

Subtract Mentally share your answer and strategy with a partner 45 – 27

Subtract Mentally 81 - 76

Is this a correct way to solve the subtraction problem? 62 – 35 60 – 35 = 35 35 – 2 = 33 The answer is 33

True or False 56 – 34 = 20

Which word problem describes the Number Sentence? 23 – ? = 11 I have 11 cupcakes left after bringing the class 23. Some student were absent. How many students were absent? 23 students were in the class and 12 more joined the class. I had 23 pencils and some rolled off my desk. I had a total of 11 still on my desk. How many rolled off?