Your child is learning about multiplying and dividing positive and ...€¦ · Your child is...
2
Dear Family, ©Curriculum Associates, LLC Copying is not permitted. 27 Lesson 4 Multiply and Divide Positive and Negative Integers Your child is learning about multiplying and dividing positive and negative integers. Use with Ready Instruction Lesson 4 Here are some examples of multiplying and dividing positive and negative integers that may be familiar to you. • You set up an automatic deduction of a whole-dollar amount from a bank account each month to pay a bill. You can multiply the negative amount deducted by the number of months to find the amount deducted over a period of several months. • You set up an automatic deposit of a whole-dollar amount to a savings account. You can multiply the positive amount deposited by the number of months to find the total amount deposited over a period of several months. • A plane descends a number of feet in a number of seconds. You can divide the negative number of feet by the number of seconds to find the negative change in the plane’s elevation per second. Here are the rules for multiplying positive and negative integers. positive 3 positive 5 positive positive 3 negative 5 negative negative 3 positive 5 negative negative 3 negative 5 positive Consider the following example: A news account reported that the price of a stock dropped by 4 dollars a day for each of 3 consecutive days. How much did the stock price change over the 3 days? NEWS On the next page you will see two different ways your child may use integer multiplication to find the amount that the price of the stock dropped.
Transcript of Your child is learning about multiplying and dividing positive and ...€¦ · Your child is...
Dear Family,
©Curriculum Associates, LLC Copying is not permitted. 27Lesson 4 Multiply and Divide Positive and Negative Integers
Your child is learning about multiplying and dividing positive and negative integers.
Use with Ready Instruction Lesson 4
Here are some examples of multiplying and dividing positive and negative integers that may be familiar to you.
• You set up an automatic deduction of a whole-dollar amount from a bank account each month to pay a bill. You can multiply the negative amount deducted by the number of months to find the amount deducted over a period of several months.
• You set up an automatic deposit of a whole-dollar amount to a savings account. You can multiply the positive amount deposited by the number of months to find the total amount deposited over a period of several months.
• A plane descends a number of feet in a number of seconds. You can divide the negative number of feet by the number of seconds to find the negative change in the plane’s elevation per second.
Here are the rules for multiplying positive and negative integers.
positive 3 positive 5 positive positive 3 negative 5 negative negative 3 positive 5 negative negative 3 negative 5 positive
Consider the following example:
A news account reported that the price of a stock dropped by 4 dollars a day for each of 3 consecutive days. How much did the stock price change over the 3 days?
NEWS
On the next page you will see two different ways your child may use integer multiplication to find the amount that the price of the stock dropped.
©Curriculum Associates, LLC Copying is not permitted.28 Lesson 4 Multiply and Divide Positive and Negative Integers
Multiply and Divide Positive and Negative Integers: Sample Solution
A news account reported that the price of a stock dropped by 4 dollars a day for each of 3 consecutive days. How much did the stock price change over the 3 days?
The change in the price of the stock can be represented by 24. To find the total drop in the stock price you need to multiply 24 by 3.
One way: Use repeated addition to represent multiplication.
The stock price dropped 4 dollars on each of 3 days.
3 groups of 24 5 (24) 1 (24) 1 (24)
5 212
Another way: Use a number line to represent multiplication.
Start at 0 and make 3 jumps of 24.
022242628210212
24 24 24
214
3 • (24) 5 212
Answer: Both methods show that multiplying 24 by 3 gives a result of 212. This means that the stock price changed by 212 dollars over the 3 days.
