N 6.4 test

 Click on the link below to complete the multiplication and division test.

https://forms.gle/Cv1Ywv5Hj7FmnLEp7

Dividing decimals

 Practice dividing using decimals by clicking the link below!

https://forms.gle/z4dQYWhSzxrsgpwE8

Multiplying decimals

 Now that you have learned to multiply decimals, practice in the form below.

https://forms.gle/D7HzvLXPcK48ggPZA

Dividing decimals by a whole number

 Watch the following video about dividing with decimals.

After watching the above video click the link below and complete the assignment.

https://forms.gle/usYngiCXdzkgSTES8

Multiplying Decimals

 Watch the following video on multiplying decimals.

After watching the video, complete the assignment below.

https://forms.gle/RLrtkroqQ5k4b88x9

 

Key terminology:

Product:  The answer when you multiply. Ex in the multiplication sentence 3x5=15, the product of 3x5 is 15.

Quotient: The answer when you divide.  Ex. The quotient in the division sentence 2.4 ÷ 6 = 0.4, the quotient of 2.4 ÷ 6 is 0.4

Estimate:  Close to an amount or value, but not exact.

The type of estimation we will be using is benchmarks.  We look at which whole number the decimal is closest to in order to estimate its value.  For example, if I have 2.73, I would estimate the value as 3, since 2.73 is closer to 3 than 2.  If I have 1.47, I would estimate the value as 1, since 1.47 is closer to 1 than 2.

An example of when I may want to estimate like this is when I go shopping.  It is easier to add the whole numbers in my head than it is decimals, so I estimate each cost to add together.  This way I can be sure I don't go over budget when shopping.

If I bought the following items for each price I can estimate how much I will spend:

Bread:  $1.47            which is about  $1

Milk:  $ 2.86             which is about  $3

Ham:  $14.97            which is about $15  

Yogurt: $3.85            which is about $4

Mayonnaise:  3.68     which is about $4

toilet paper: $20.42   which is about $20

oranges:  $6.42          which is about $6

If I add my estimates together, I get $53, which is close to the actual amount.  If I add all of the actual amounts together, I get $53.67.  Using benchmarks is the type of estimation that will get you the closest to the actual amount.

Using benchmarks can also be useful for multiplying and dividing decimals as well.  For example:

The mass of 8 ping pong balls is 23.84 g.  How much does 1 ping pong ball weigh?

I can say that 23.84 is close to 24. So I write the following sentence:

24 ÷ 8 = 3

Each ping pong ball weighs about 3 grams.

To multiply I can do something similar. For example, if 1 baseball has a mass of 143.985, What is the mass of 4 baseballs?  I would write the following:

143.985 is closest to 144 so, 

144 x 4 = 576

The mass of 4 baseballs is about 576 g.

Click on the following link to complete the assignment.  Use estimates to find the answers.

https://forms.gle/6xnzCfN8e18vjo5c7

Decimals

Key terminology:

ten-thousandths

hundred-thousandths

millionths

Place value Chart

In grade 5 we worked on place value to the millions, and ten thousandths.  The chart above shows the number 27 in a place value chart.  If I divide 27 by 50 using my calculator, I will get 0.54.  If I divide that by 50, I get 0.0108.  Now, If I divide that by 25, I get 0.000432.  Each of those written in the place value chart will look like this:

In the chart, I had to fill in ten-thousandths, hundred-thousandths and millionths.  The place value chart follows the same pattern after the decimal as it does before.  We add the letters "ths" onto the end of the words to indicate they are after the decimal.  The only one that we do not include after the decimal is ones.  There is NO such thing as oneths.  

Read the following page to look at the patterns in the place value chart.

If we look at the number 3.268 579, we would write it in expanded form as:

3 ones + 2 tenths + 6 hundredths + 8 thousandths + 5 ten-thousandths + 7 hundred-thousandths + 9 millionths

= 3 + 0.2 + 0.06 + 0.008 + 0.0005 + 0.000 07 + 0.000 009

We read this decimal as: three and two hundred sixty eight thousandths, five hundred seventy-nine millionths.  Look at the examples in the picture below.

Click on the link below to practice place value with decimals.

https://forms.gle/wYGwgPpAdAfsjH4M7