Transcript 6-5 Multiplying and Dividing Decimals

Multiply with decimals
Standard UW.GAP.5.M.NBT.07 Add, subtract,
multiply, and divide decimals to hundredths using
concrete models or drawing and strategies based on
place value, properties of operations, and/or the
relationship between addition and subtraction; relate
the strategy to a written method and explain the
reasoning used.
Essential Questions
1.
What is addition? How do you add
decimals?
2.
What is subtraction? How do you subtract
decimals?
3.
What is multiplication? How do you use a
model and partial products to represent multiplying
decimals?
4.
What is division? How do you use a model
and partial products to represent dividing decimals?
Set....
Think about the strategies we use to multiply
whole numbers....
Take turns with your face partner and describe
how we multiply and divide whole numbers.
Objective: I can
multiply decimals
to hundredths
place.
Let’s
Reviewof tenths, hundredths, etc.
Decimal - a number with
a fraction
written after a decimal point.
Decimal point - the (.) between a whole number and fractions of
tenths, hundredths, thousandths, etc.
Digit- any of the numerals 0-9, which may be part of a larger
number.
24.56 x 4 . 1 = 100.696
Think back to Adding and
Subtracting Decimals
Step 1- line up the decimals
Step 2- add any place holding zeros
Step 3 - add or subtract like you always do
Step 4 - bring the decimal straight down
Multiplication is much different, let’s learn how...
Rules for Multiplying
Decimals
When multiplying decimals, multiply
just like normal then move decimal
over to the right, then move decimal
that many place in answer to the left.
Multiplying Decimals
Example 1
Solve = 10.7 x 0.13
10.7
1 decimal place
Multiplying Decimals
Example 1
Solve = 10.7 x 0.13
1 decimal place
10.7
2 decimal places
x0.13
Multiplying Decimals
Example 1
Solve = 10.7 x 0.13
1 decimal place
10.7
2 decimal places
x0.13
321
Multiplying Decimals
Example 1
Solve = 10.7 x 0.13
10.7
1 decimal place
x0.13
2 decimal places
321
1070
Multiplying Decimals
Example 1
Solve = 10.7 x 0.13
1 decimal place
10.7
2 decimal places
x0.13
321
+1070
3 decimal places
1.391
Let’s watch how to
multiply with models
http://www.slideshare.net/slideshow/embed_cod
e/9425239
Let’s try one together...
4.56 x .83
Now you try
16.73 x 4.89
Closure
Think about what is different about multiplying whole
numbers and multiplying decimals
On your slate: Write a $2 summary explaining what
is different
Repeat todays objective
Independent Practice
1. 45.2 x 2.3=
2. 98.01 x 7=
3. 6.6 x 4.9
4. 39.4 x 23.09=
5. 6.34 x 23 =
6. 10.6 x 15.3=
7. 99.23 x 34=
8. 7.34 x 2.34=