Tuesday, Oct 30

5 Minute CheckComplete in your notebook. Estimate each product. 1. 9.7 x 32. 3.4 x 53. 17.5 x 8Multiply.4. 1.5 x 65. 3.1 x 136. 3.48 x 255 Minute CheckComplete in your notebook. Estimate each product. 1. 9.7 x 35 Minute CheckComplete in your notebook. Estimate each product. 1. 9.7 x 3 10 x 3 = 305 Minute CheckComplete in your notebook. Estimate each product. 2. 3.4 x 55 Minute CheckComplete in your notebook. Estimate each product. 2. 3.4 x 5 3 x 5 = 155 Minute CheckComplete in your notebook. Estimate each product. 3. 17.5 x 8 5 Minute CheckComplete in your notebook. Estimate each product. 3. 17.5 x 8 18 x 8 = 1445 Minute CheckComplete in your notebook. Multiply.4. 1.5 x 6 5 Minute CheckComplete in your notebook. Multiply.4. 1.5 x 6 1.51 decimal place x 6 9.01 decimal place5 Minute CheckComplete in your notebook. Multiply.5. 3.1 x 135 Minute CheckComplete in your notebook. Multiply.5. 3.1 x 13

3.11 decimal place x 1 3 Dont forget the zero 93 + 310 40.31 decimal place

5 Minute CheckComplete in your notebook. Multiply.6. 3.48 x 25

5 Minute CheckComplete in your notebook. Multiply.6. 3.48 x 25

3.482 decimal places x 25 Dont forget the zero 1740 + 6960 87.002 decimal places

Flashcards!

Wednesday, Oct 9Lesson 3.2 and 3.4

Multiplying Decimals by DecimalsMultiplying Decimals by DecimalsObjective: To understand how to estimate and multiply decimals by decimals.

Multiplying Decimals by DecimalsAt the end of this lesson you should be able to answer the following questions.

How do you determine which place value to use when multiplying decimals by decimals?

Why is estimating not as helpful when multiplying very small numbers?

Multiplying Decimals by DecimalsTo multiply decimals, multiply as normal and then place the decimal point. Multiplying Decimals by DecimalsFind the product of 8.7 and 2.8.

First round the numbers to the nearest whole number to get an estimate.

What does 8.7 round to?

Digits from 0 to 4 round down and digits from 5-9 round up.

Multiplying Decimals by DecimalsFind the product of 8.7 and 2.8.

First round the numbers to the nearest whole number to get an estimate.

What does 8.7 round to? 9

What does 2.8 round to?

Multiplying Decimals by DecimalsFind the product of 8.7 and 2.8.

First round the numbers to the nearest whole number to get an estimate.

What does 8.7 round to? 9

What does 2.8 round to? 3

Multiplying Decimals by DecimalsFind the product of 8.7 and 2.8.

First round the numbers to the nearest whole number to get an estimate.

9 x 3 = 27, so

8.7 x 2.8 27

Multiplying Decimals by DecimalsFind the product of 8.7 and 2.8.To multiply decimals.Step 1 Stack the numbers with the number with the most digits on top. 8.7 x 2.8

(Since both numbers have 2 digits, either could be on top)

Multiplying Decimals by DecimalsFind the product of 8.7 and 2.8.To multiply decimals.Step 2 Multiply the digits.

8.7 x 2.8 696 Dont forget to add the zero.+1740 2436

Multiplying Decimals by DecimalsFind the product of 8.7 and 2.8.To multiply decimals.Step 3 Determine the number of decimal places in the factors to locate the decimal place in the product. 8.7 1 decimal place x 2.8 + 1 decimal place 696 +1740 24.36 2 decimal places

Multiplying Decimals by DecimalsFind the product of 8.7 and 2.8. 8.7 x 2.8 696 +1740 24.36

Is this a reasonable answer?

Multiplying Decimals by DecimalsFind the product of 8.7 and 2.8.

Is this a reasonable answer?

24.35 27

Multiplying Decimals by DecimalsFind the product of .98 and 7.3

Estimate?

Multiplying Decimals by DecimalsFind the product of .98 and 7.3

Estimate?

1 x 7 = 7, so.98 x 7.3 7

Next?

Multiplying Decimals by DecimalsFind the product of .98 and 7.3

.98 x 7.3

Next?

Multiplying Decimals by DecimalsFind the product of .98 and 7.3

.98 x 7.3 294 Dont forget to add a zero +6860 7154

Next?

Multiplying Decimals by DecimalsFind the product of .98 and 7.3

.98 2 decimal places x 7.3 +1 decimal place 294 +6860 7.154 3 decimal places

Is this a reasonable answer?

Multiplying Decimals by DecimalsFind the product of .98 and 7.3

.98 2 decimal places x 7.3 +1 decimal place 294 +6860 7.154 3 decimal places

Is this a reasonable answer?7.154 7

Multiplying Decimals by DecimalsFind the product of 3.6 and 0.05.

Estimate?

Multiplying Decimals by DecimalsFind the product of 3.6 and 0.05.

4 x 0 = 0, so

3.6 x 0.05 0

Multiplying Decimals by DecimalsFind the product of 3.6 and 0.05.

4 x 0 = 4, so

3.6 x 0.05 0

Actual product?

Multiplying Decimals by DecimalsFind the product of 3.6 and 0.05

0.05 2 decimal places x 3.6 +1 decimal place 0030 + 0015 0.045 3 decimal places

Is this a reasonable answer?

Multiplying Decimals by DecimalsFind the product of 3.6 and 0.05

0.05 2 decimal places x 3.6 +1 decimal place 030 +0150 0.180 3 decimal places

Is this a reasonable answer?0.180 0

Multiplying Decimals by DecimalsFind the product of 0.112 and 7.2

Estimate?

Multiplying Decimals by DecimalsFind the product of 0.112 and 7.2

Estimate?

0 x 7 = 0, so

0.112 x 7.2 0

Actual product?

Multiplying Decimals by DecimalsFind the product of 0.112 and 7.2

0.112 3 decimal places x 7.2 +1 decimal place 0224 +07840 .8064 4 decimal places

Is this a reasonable answer?

Multiplying Decimals by DecimalsFind the product of 0.112 and 7.2

0.112 3 decimal places x 7.2 +1 decimal place 0224 +07840 .8064 4 decimal places

Is this a reasonable answer?0.8064 0

Multiplying Decimals by DecimalsFind the product of 1.4 and 0.067

Estimate?

Multiplying Decimals by DecimalsFind the product of 1.4 and 0.067

Estimate?1 x 0 = 01.4 x 0.067 0

Actual product?

Multiplying Decimals by DecimalsFind the product of 1.4 and 0.067

0.067 3 decimal places x 1.4 +1 decimal place 0268 +00670 0.0938 4 decimal places

Is this a reasonable answer?

Multiplying Decimals by DecimalsFind the product of 1.4 and 0.067

0.067 3 decimal places x 1.4 +1 decimal place 0268 +00670 0.0938 4 decimal places

Is this a reasonable answer?0.0938 0

Multiplying Decimals by DecimalsMr. Averys car can travel 28.45 miles on one gallon of gas. If his gas tank holds 11.5 gallons, how far can he travel on one tank?

Estimate?

Multiplying Decimals by DecimalsMr. Averys car can travel 28.45 miles on one gallon of gas. If his gas tank holds 11.5 gallons, how far can he travel on one tank?

Estimate?

28 x 12 = 336Keep in mind 28 x 12 = 28 x 10 + 28 x 2 = 280 + 56 = 336Actual product?

Multiplying Decimals by DecimalsMr. Averys car can travel 28.45 miles on one gallon of gas. If his gas tank holds 11.5 gallons, how far can he travel on one tank?

28.45 2 decimal places x 11.5 +1 decimal place 14225 28450 +284500 327.175 3 decimal places

Is this a reasonable answer?

Multiplying Decimals by DecimalsMr. Averys car can travel 28.45 miles on one gallon of gas. If his gas tank holds 11.5 gallons, how far can he travel on one tank?

28.45 2 decimal places x 11.5 +1 decimal place 14225 28450 +284500 327.175 3 decimal places

Is this a reasonable answer? 327.175 336

Multiplying Decimals by DecimalsDetermine whether the following statement is always, sometimes or never true. The product of two decimals less than 1 is less than either of the factors.

Give examples to support your answer.

Multiplying Decimals by DecimalsDetermine whether the following statement is always, sometimes or never true. The product of two decimals less than 1 is less than either of the factors. Always.0.3 x 0.5 = .15, which is less than 0.3 and 0.5

0.75 x 0.6 = 0.45

Multiplying Decimals by DecimalsComplete the Mid-Chapter Check on page 214. When complete bring to the desk and show Mr. Avery. Agenda NotesHomework Homework Practice 3-2/3-4Due Thursday, Oct 10

Mid-Chapter 3 Quiz Thursday, Oct 10