Addition and Subtraction

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​Addition and Subtraction Strategies

By Mr. James

​Objective:

I can add and subtract multi-step word problems, by representing them using diagrams and different algorithms

Poll

How are you feeling today?

Addition Properties

Associative Property

When we add three or more numbers, the sum is the same regardless of the grouping of the addends. It also means that when we add three different numbers, the answer is not affected by the addition pattern followed.

For example, (4 + 2) + 3 = 4 + (3 + 2)

It also has these things ------- ( ) which are called parenthesis

Multiple Choice

What are these called?

( )

• the letter c

• symbols

• parenthesis

Commutative Property

When we add two or more numbers, their sum is the same regardless of the order of the addends. We can write this property in the form of A + B = B + A.

For example,  2+4 = 4 + 2

Identity Property

Adding with Zero

When you add with zero, the answer will remain the same.

6+0= 6
7+0= 7
1,203 + 0 = 1,203

POP QUIZ!

Multiple Choice

Which Property is this?

40,454 + 0 = 40,454

• Associative

• Commutative

• Identify

Multiple Choice

Which Property is this?

• Associative

• Commutative

• Identify

Multiple Choice

Which Property is this?

(2 + 3) + 4 = 2 + (3 + 4) = 9

• Associative

• Commutative

• Identify

Multiple Choice

Which Property is this?

(8 + 2) + 1 = 8 + (2 + 1) = 11

• Associative

• Commutative

• Identify

Multiple Choice

Which Property is this?

4 + 6 = 6 + 4

• Associative

• Commutative

• Identify

Multiple Choice

Which Property is this?

4 + 6 = 6 + 4

• Associative

• Commutative

• Identify

Multiple Choice

Carl modeled an addition property with the equation below.

0 + 14 = □

• 0

• 14

• 7

Multiple Choice

Carsen Smith wants to find the sum of 85 + 15 + 21 mentally. Show a way she can do this by using a property of addition.

• She could use the Identity Property: 85 + 21 + 0 + 15

• She could use the Communitive Property: 85 + 15 = 21

• She could use the Associative Property:(85 + 15) + 21 =100 + 21 = 121

Adding and Subtracting Strategies

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​When adding and subtracting you can do it one or two ways.

Standard Algorithm | Expanded Algorithm

967
982

+

900 + 60 +7
900 + 80 + 2

+

Multiple Choice

Nancy has 966 baseball cards. Tim bought 109 of Nancy's baseball cards. How many baseball cards does Nancy have now?

• 856

• 857

• 223

• 984

Day 2 | Representing Addition and Subtraction Problems

Poll

Multiple Choice

Click the picture to answer the question

• A

• B

• C

Multiple Choice

Mr. Thompson sold 247 meals on Tuesday at his restaurant. He sold 516 meals on Wednesday. What is the difference between the number of meals Mr. Thompson sold on these two days?

• 763

• 331

• 379

• 269

Multiple Choice

The students in Mr. Baxley's class planted 24 seeds for a class project. So far, 15 of the seeds have sprouted. Which equation could be used to determine the number of seeds that have not yet sprouted?

Multiple Choice

Answer this question

• A

• B

• C

• D

Multiple Choice

Multiple Choice

Multiple Choice

Multiple Choice

Multiple Choice

Multiple Choice

• A

• B

• C

• D

Open Ended

Loryn bought a specialty purse for $288 and a matching wallet for $119. Both prices included tax. She gave the clerk $500. How much change should Loryn have received? Show your work.