Properties and Operations of Numbers

This video tutorial covers the multiplication of rational numbers, focusing on decimals and fractions. It explains the use of commutative and associative properties to simplify multiplication and discusses how to determine the sign of a product based on the number of negative factors. The tutorial includes practical examples and encourages students to practice using these concepts.

What is the first step when multiplying decimals?

• Ignore the decimal places and multiply

• Add the decimal places together

• Line up the decimal places

• Convert to fractions

How do you determine where to place the decimal in the product of two decimals?

• Count the total number of decimal places in both factors

• Place the decimal at the end

• Use the larger number's decimal places

• Divide the number of decimal places by two

What should you do if you can't cross-cancel when multiplying fractions?

• Subtract the fractions

• Convert to decimals

• Multiply straight across

• Add the fractions

What is the commutative property of multiplication?

• Changing the grouping of numbers

• Changing the order of numbers

• Multiplying by zero

• Multiplying by one

What is the associative property of multiplication?

• Multiplying by one

• Multiplying by zero

• Changing the order of numbers

• Changing the grouping of numbers

What happens when you multiply an even number of negative numbers?

• The result is negative

• The result is positive

• The result is undefined

• The result is zero

What happens when you multiply an odd number of negative numbers?

• The result is negative

• The result is positive

• The result is zero

• The result is undefined

What is the denominator of a whole number when written as a fraction?

• 1

• 10

• 100

• 0

In the example problem, why is the associative property used?

• To change the order of multiplication

• To subtract the fractions

• To add the fractions

• To simplify the multiplication

What is the final result of the example problem given in the video?

• -42

• 42

• -6

• 6