Multiplication and Division

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Transcript Multiplication and Division

Oh yeah we’ve got this!
1)
2)
Write down 3 goals that you have
for this unit!
Then write down 3 things you will
do to help you reach those goals.
Make sure to set high
expectations for yourself and then
do what it takes to meet those
goals!
 MCC6.NS.2
Fluently divide multi-digit
numbers using the standard algorithm.
How is multiplication related to division?
 BrainPop

Video
http://www.brainpop.com/math/numbersandop
erations/multiplication/
So now let’s move it up to a 6th
grade level!
Step 1: Multiply
625  4
625
x34
2500
Solution:
21,250
Problem:
625  34
Step 2: Multiply
625  30
625
x34
2500
18750
Step 3: Add
2500 + 18750
625
x34
2500
+18750
21250
Step 1: Multiply
492  8
492
x28
3936
Solution:
13,776
Problem:
492  28
Step 2: Multiply
492  20
492
x28
3936
9840
Step 3: Add
3936 + 9840
492
x28
3936
+9840
13776
523
x41
Solution:
21,443
645
x16
Solution:
10,320
 Find
the product!
4234
x23
Solution:
97,382
2198
x35
Solution:
76,930
 MCC6.NS.2
Fluently divide multi-digit
numbers using the standard algorithm.
Please pick up all 3 papers on the warm-up
table. Then, find the quotient of the following
two problems.
5 425
Solution:
85
3 522
Solution:
174
 Algorithm
a
specific set of instructions for carrying out
a procedure or solving a problem
 Method, procedure, technique
Now you can
sound super
smart! :)
 http://learnzillion.com/lessons/1678-divide-
4digit-numbers-by-2digit-numbers-using-longdivision-no-remainder
 In
long division, there are three steps that
you keep doing until you reach your goal!
Divide
Bring it Down
Multiply
Subtract
Zero after subtraction and
no number to bring down!
 Think
of it as an 18-wheeler truck.
In the back are all of your
supplies that haven’t been
placed in boxes yet.
You are the driver and know
how many boxes the company
needs delivered.
 You
need to deliver 3654 boxes of Girl Scout
cookies. You have been able to find 42 large
cardboard boxes to put the cookies in. How
many boxes of cookies can go in each
cardboard box?
42 3654
Step one: How many
times does 42 go into
365? (Divide)
Strategy: Guess and Check
42 • 5 = 210 (way too small)
42 • 9 = 378 (over!)
42 • 8 = 336 (Oh YEAH!)
Step three: Subtract 336
from 365.
Step two: Place the 8 above
the final place value of the
365. Multiply 8 and 42 to
get 336.
Step four: Bring down the 4
87
42 3654
-336
294
-294
Strategy: Guess and Check
42 • 5 = 210 (way too
small)
42 • 7 = 294 (Perfect!)
0
Complete Answer
You can put 87 boxes of Girl
Scout cookies in each
cardboard box.
 Remainder:
is what fraction of the whole is
going to be left over.
 You
are buying a game with your 4 friends
that costs $28. How much does each person
owe?
How do you set
up this
problem?
 Instead
of using a R remainder,
just keep dividing and form a decimal.
5 R3
5 28
-25
3
5.6
5 28.0
-25
30
-30
0
THEN
NOW
Strategy:
Guess and Check
16 • 2 = 32
16 • 3 = 48
Strategy:
Guess and Check
16 • 9 = 144
16 • 8 = 128
28.2 5
16 452.0 0
-32
132
-128
40
-32
80
-80
0
Strategy:
Guess and Check
16 • 5 = 80
 Our
class with 28
people wants to go
on a trip to the
aquarium. They
gave us a group rate
of $595 for
everyone. How
much does each
student have to
pay?
Each student in the
class would pay $21.25.
 My
3 roommates
and I want to buy
new living room
furniture. We
found some that
costs $2499. How
much would each
of us have to pay?
Each roommate would
have to pay $624.75.
 Find
the quotient!
41 87248
Solution:
2,128
24 2328
Solution:
97
 Sarah’s
annual
salary is $65,013.
If she works all 52
weeks of the year,
how much is she
paid each week?
Sarah makes
$1250.25 per week.
 The
distance from
New York to Tokyo
is 6,375 miles. If it
takes 15 hours to
fly from NY to
Tokyo, how many
miles per hour is
the plane flying?
The plane flies at
425 miles per hour.
 In
2012, Taylor Swift’s concert tour grossed
approximately $26,310,144 over her 21
shows. How much money did each concert
make on average?
Taylor Swift’s concerts
made $1,252,864 on
average.
 MAKE
SURE TO PICK UP THE NOTETAKING
SHEET AND HOMEWORK FROM THE BACK
TABLE!!
 Last
year, Abby made $33,300. How much
money did Abby make each month?
Abby made $2775 per
month.
 The
key is ESTIMATION!!!
 Estimation helps you make sure that your
answer makes sense.
242÷2.2= ?
 Now
240÷2= 120
make sure that your answer is
reasonably close to the estimation.
1)
You cannot have any decimals on the
outside of the division sign, so you have to
move the decimal.
2.2 242 0
Move the decimal
until it is a whole
number!
Place a 0 in
each place
value where
you moved
the decimal
Then move the decimal
the same amount of
spaces on the number
under the division sign.
2) Use the standard division algorithm.
110
22 2420
-22
22
-22
00
-0
0
3) Check and make sure your answer is
reasonable.
12 50.28
.42 5.124
4.19
12.2
 There
is only one difference between
multiplying whole numbers and decimals…
1) Estimate! 3 • 1 = 3
3.456
x 1.3
10368
+34560
44928
44928
.
2) Use your
imagination and
pretend the decimals
aren’t there
3) Use the standard
multiplication
algorithm
4) Count the number
of digits located to the
right of the decimal
5) Do the Decimal
Dance!
10.47
X .92
9.6324
65.2
x.245
15.974
 Sawyer
is saving $6.35 a week to buy a
video game that costs $57.15. How many
weeks will he have to save to buy the
video game?
Sawyer will have to save for 9
weeks to afford the video game.
 http://www.khanacademy.org/math/arithme
tic/multiplicationdivision/long_division/e/division_3