Day…..1 – Multiplying Decimals by Whole N
umbers
2 – Multiplying Decimals by Decimals
3 – Dividing Decimals by Whole Number
s
4 - Dividing Decimals by Decimals
5 – Exploring Decimals
Bell Work
The Steven’s Family drove 258 miles a day
for 3 days. How many miles did the drive in
all?
Justify your answer.
If they continued to travel at this rate, how
many miles would they drive in a week?
VocabularyCompatible numbers-
Decimal -
Factors-
Dividend-
Divisor -
Estimate-
Product-
Quotient-
a reasonable guess
The number you divide by
The amount being divided
a representation of a real number using the base ten and decimal notation, such as 201.4, 3.89, or 0.0006. (Part of a Whole)
numbers that are easily multiplied or divided mentally.
Numbers being multiplied in a multiplication equation
the answer to a multiplication equation
the answer to a division equation
Multiply Decimals by Whole Numbers
• Essential Understanding: Use the basic rules of multiplication when multiplying a decimal by a whole number or other decimal. To place the decimal in the product, count the number of decimals places in each factor.
Example: 3 x .02 = .06 there are two decimal places in the factors. So, there will be two decimal places in the product.
Guided Practice: Complete Problems 1-8 on page 30
Bell WorkLouisa walked her dog 0.4 miles a day on
Tuesday, Wednesday, Thursday, and Friday.
Find the total distance she walked all week.
Justify your answer.
If Louisa continued to walk her dog at this rate how far would she walk in 4 weeks?
VocabularyCompatible numbers-
Decimal -
Factors-
Dividend-
Divisor -
Estimate-
Product-
Quotient-
a reasonable guess
The number you divide by
The amount being divided
a representation of a real number using the base ten and decimal notation, such as 201.4, 3.89, or 0.0006. (Part of a Whole)
numbers that are easily multiplied or divided mentally.
the answer to a multiplication equation
the answer to a division equation
Numbers being multiplied in a multiplication equation
Multiplying Decimals by Decimals
• Essential Understanding: Use the basic rules of multiplication when multiplying a decimal by a whole number or other decimal. To place the decimal in the product, count the number of decimals places in each factor.
Example: 1 .5 x 1.5 = 2.25 There are two decimal places in the factors. So, there will be two decimal places in the product.
Guided Practice: Complete Problems a-f on pages 38-39
Bell WorkJunnie walked for 2.5 hours at a speed of 2.3
miles per hour. Maurice walked for 1.8 hours
at a speed of 4.1 miles per hour. Who walked
farther?
Justify your answer.
(Hint: Distance = speed x time)How much farther did Junnie Walk?
VocabularyCompatible numbers-
Decimal -
Factors-
Dividend-
Divisor -
Estimate-
Product-
Quotient-
a reasonable guess
The number you divide by
The amount being divided
a representation of a real number using the base ten and decimal notation, such as 201.4, 3.89, or 0.0006. (Part of a Whole)
numbers that are easily multiplied or divided mentally.
the answer to a multiplication equation
the answer to a division equation
Numbers being multiplied in a multiplication equation
Dividing Decimals by Whole Numbers
• Essential Understanding: Use the basic rules of division. Since there is not a decimal in the divisor, you can simply bring the decimal of the dividend up and divide as normal.
Guided Practice: Complete Problems 1-4 on page 48
Bell Work
Ryan and his brother are sharing the cost
of a video game. The game cost $28.60.
How much does each brother have to pay?
Justify your answer.
If Ryan saves $20 for the game, how much money will he have left?
VocabularyCompatible numbers-
Decimal -
Factors -
Dividend-
Divisor -
Estimate-
Product-
Quotient-
a reasonable guess
The number you divide by
The amount being divided
a representation of a real number using the base ten and decimal notation, such as 201.4, 3.89, or 0.0006. (Part of a Whole)
numbers that are easily multiplied or divided mentally.
the answer to a multiplication equation
the answer to a division equation
Numbers being multiplied in a multiplication equation
Dividing Decimals by Decimals
• Essential Understanding: Use the basic rules of division. To divide any number by a decimal, you must first change the divisor into a whole number. This is done by multiplying it by some power of 10. Then multiply the dividend by the same power of 10. Finally, bring the decimal up and divide as usual.
In other words, move the decimal of the outside number to the end. Then move the decimal of the inside number the same number of places. Finally bring inside decimal straight up and divide.
Guided Practice: Complete Problems 1-6 on pages 54-55
Bell WorkThe longest vehicle tunnel in the world is the
Laerdal Tunnel in Norway with a length of 15.2
miles long. How many vehicles could fit in the
tunnel, bumper to bumper, if the average
vehicle’s length is 0.004 mile?
Justify your answer.
VocabularyCompatible numbers-
Decimal -
Factors -
Dividend-
Divisor -
Estimate-
Product-
Quotient-
a reasonable guess
The number you divide by
The amount being divided
a representation of a real number using the base ten and decimal notation, such as 201.4, 3.89, or 0.0006. (Part of a Whole)
numbers that are easily multiplied or divided mentally.
the answer to a multiplication equation
the answer to a division equation
Numbers being multiplied in a multiplication equation