Using the Commutative and Associative Properties to Add 2-Digit Numbers

This video tutorial teaches how to add two 2-digit numbers using the commutative and associative properties. It begins with an introduction to these properties, followed by examples demonstrating their application. The tutorial also covers the concept of place value and how to use open number lines for addition. Through examples, viewers learn to break down numbers into tens and ones, apply properties, and use number lines to find sums efficiently.

What does the commutative property of addition state?

• Numbers can only be added if they are the same.

• Numbers must be added in a specific order to get the correct sum.

• Numbers can be added in any order to get the same sum.

• Numbers cannot be added if they are in different orders.

How does the associative property of addition help in adding numbers?

• It requires numbers to be grouped in a specific order.

• It does not affect the order of addition.

• It allows numbers to be grouped in any order to get the same sum.

• It only applies to subtraction.

What is the value of the digit '4' in the number 46?

• 0.4

• 40

• 4

• 400

How can open number lines be used in addition?

• By jumping by tens or ones to find the sum.

• By subtracting numbers directly.

• By multiplying numbers.

• By dividing numbers.

When adding 57 and 35, what is the sum of the tens?

• 80

• 70

• 90

• 100

In the example of adding 57 and 35, what is the final sum?

• 92

• 87

• 97

• 82

What is the result of adding 49 and 18?

• 57

• 67

• 87

• 77