enVision Math Grade 5- Adapted NotesName- ______

Topic 6 Lesson 1- Multiplying Decimals by 10, 100, or 1,000

Objective: Mentally multiply decimals by 10, 100, or 1,000.

Recall: Exponential formStandard formExample

______

______

______

** Think about how many 0s are being multiplied and that will move the decimal that many places to the ______. **

** Also you can look at the exponent and that will tell us how many places to move to the ______

Examples:

  1. A baker needs to purchase 10 lbs. of pecan and 100 lbs of flour. How much will the baker spend for each ingredient?
  2. Flour= $0.45/lbs.
  3. Pecan= $2.89/lbs.

PecanFlour

______

OrOr

______

  1. 0.426 x 10 = ______

Or

0.426 x 100= ______

enVision Math Grade 5- Adapted NotesName- ______

Topic 6 Lesson 2- Estimating the Product of a Decimal and Whole Number

Objective: Use rounding and compatible numbers to estimate products of whole numbers and decimals. Identify estimates as overestimates or underestimates.

** There are two options for this lesson**

Option 1- Round each ______

Option 2- Use ______that you can use to multiply mentally

Examples

  1. A planner for a wedding needs to buy 16 pounds of sliced cheddar cheese. About how much will the cheese cost? Cheese costs $2.15 per pound.

Option 1Option 2

______

______

Cheese will cost about ______Cheese will cost about ______

  1. Manuel found the total distance he walks to and from school is equal to 0.75 mile. If Manuel walks to and from school 184 days in one year, about how many total miles will he walk?

Option 1Option 2

______

______

Homework Help

** Be sure to place the decimal in the correct place.**

** Estimating is helpful before getting the actual product because an estimate that is very different from the actual product will alert you to go back and check your work!**

enVision Math Grade 5- Adapted NotesName- ______

Topic 6 Lesson 3- Number Sense: Decimal Multiplication

Objective: Use number sense and place value to multiply decimals.

There are two options in solving problems within this lesson.

Option 1:

Multiplying a number by a decimal less than 1 give you a product that is ______than the other factor this will help you think about where to place the decimal.

Example 15 x 0.75= ______

Option 2:

Another way to find where to place the decimal is to count the number of decimal places in the problem. After getting that number you will move the decimal point that number of place to the ______.

Example 20 x 0.85=______

Example

  1. $45.30 x 0.55

SHOW YOUR WORK

enVision Math Grade 5- Adapted NotesName- ______

Topic 6 Lesson 4- Models for Multiplying Decimals

Objective: Find products of whole numbers and decimals to ten thousandths.

** Recall: Count the number of decimal places in the problem and that answer will have us move the decimal that number of places to the ______after we are done multiplying.

Examples:

  1. Bari displayed four paintings side-by-side in one row. Each painting has the same width. What is the total width of the four paintings? (each width is 0.36 m wide)

** When we multiply by a whole number with a decimal, we continue to shade in.

  1. Find 0.5 x 0.3. Use what you know about multiplying whole numbers to multiply decimals.

** When we multiply by two decimal numbers place the one going down, and the other going across. To find the answer, we look to see what blocks are shaded in ______.

Homework Help

** You will need to add zeros to the left of the product when the number of places in the product is less than the total number of decimal places in the factors.

enVision Math Grade 5- Adapted NotesName- ______

Topic 6 Lesson 5- Multiplying a Decimal by a Whole Number

Objective: Use standard algorithm to multiply a whole number and a decimal.

** Another way to multiply a decimal is to change the decimal into a whole number by multiplying by powers of 10.

** When we are at the end (when we get our product), we must divide to know where to place the ______to achieve the final answer.

Examples:

  1. The price of admission to a minor league baseball game increased by 0.17 times the amount of last year’s admission. If last year’s admission was $26, how much is the increase?

Step 1Step 2

Rewrite each factor as a whole #Because we multiplied 0.17 x 10^2,

by multiplying by powers of 10 we must divide our answer by 100 to

(only the decimal number)place the decimal in the right place.

______= ______= ______

______= ______

Multiply the whole numbers

______

X______

______

______

______

  1. 9.8  ______= ______= _____

x 2  ______= ______

** Homework Help #35Reduce the fraction by dividing the numerator and denominator by the same number to get the reduced fraction.

enVision Math Grade 5- Adapted NotesName- ______

Topic 6 Lesson 6- Multiplying Two Decimals

Objective: Use the standard algorithm to multiply decimals by decimals.

** When multiplying decimals by decimals, follow the following steps to find the product:

Option 1:

Step 1- ______Step 2- ______(think charts) Step 3- ______

Option 2:

Multiply each decimal number and then count the number of decimal places in the problem, then move the decimal that many places to the ______.

Example:

  1. Nancy walked 1.7 miles in 1 hour. If she walks at the same rate, how far will she walk in 1.5 hours? Multiply to find 1.7 x 1.5.

Option 1

Step 1Step 2Step 3

EstimatePartial ProductsAdd

______=______=______

______= ______= ______

______= ______

______= ______

Page 2 of Lesson 6.6

Option 2

1.7

x 1.5

Homework Help

** When multiplying by two decimal numbers, we must consider both decimal numbers by counting the number of decimal places in both decimal numbers.

** The step in using estimation is important because it will help us see if the decimal is misplaced in the actual product because it will not be close to the estimated product.

enVision Math Grade 5- Adapted NotesName- ______

Topic 6 Lesson 7- Problem Solving: Multiple-Step Problems

Objective: Find the hidden question or questions to solve multiple-step problems

Steps in solving:

  1. Identify the information ______
  2. Identify what am I ______
  3. Find the hidden ______
  4. Draw a ______
  5. Solve.

Example:

For 3 months, a fifth grade class held a fun fair to raise money for charities. The funds raised are shown in the table on page 160. If the class divides the money equally among 30 different organizations, how much will each organization receive?

Step 1Step 2Step 3

______

______

______

Step 4Step 5