Adding Decimals and Whole Numbers

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Adding Decimalsand Whole Numbers

• Lesson 1-6

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First we need to talk about the bank!
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THE BANK of MOM
Oh No! I have too much change and my pockets are
full! Who can I ask to hold my money?
No problem, Honey. I will hold it for you.
When we add, we are not allowed to hold on to any
more than 10 (0-9) pieces of money in any place
value! If we have more than that, we have to
share it with the next place value (carry it
over).
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Here is how it works
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In addition and subtraction, we only work with
money that has zeroes and ones in it--NO
quarters, nickels, or five dollar bills are
allowed!
Thats right! No two dollar billsno twenties no
fifties either
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Carrying Over in Addition
That means if I make piles of ten pennies, then I
have to give all of my full piles of 10 to the
dimes placeThen they turn my pennies into a dime
and keep it! I only get to keep what is left. ?
10 pennies 1 dime
,
x 10
penny
dime
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Change 10 pennies into 1 dime

There goes my money... ? Bye-bye pennies!
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A Penny

• It takes 100 pennies to make 1 whole dollar
• A penny is worth 1/100 of a dollar
• That is .01 as a decimal
• Notice that the 1 is in the hundredths place

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Carrying Over in Addition
That means if I make piles of ten dimes, then I
have to give all of my full piles of 10 to the
dollars placeThen they turn my dimes into a
dollar and keep it! I only get to keep what is
left. ?
Cash in 10 dimes to get 1 dollar
,
x 10
dime
dollar
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Change 10 dimes into 1 dollar

There goes my money... ? Bye-bye dimes!
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A Dime

• It takes 10 dimes to make 1 whole dollar
• A dime is worth 1/10 of a dollar
• That is .1 or .10 as a decimal
• Notice that the 1 is in the tenths place

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Carrying Over in Addition
Cash in 10 dollars to get 1 ten dollar bill
Oh, No! Not again! ?
x 10
,
dollar
ten dollars
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Change 10 one-dollar bills into 1 ten-dollar bill

There goes my money... ? Bye-bye dollars!
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Carrying Over in Addition
Cash in 10 ten-dollar bills to get 1
hundred-dollar bill
The hundreds place is taking my ten dollar bills!
Will this ever stop?
x 10
Nope! Thats how this works, Buddy!
,
Hundred dollars
ten dollars
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And now we are just pretending
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Carrying Over in Addition
Cash in 10 hundred-dollar bills to get 1
thousand-dollar bill
Could you imagine having to hand the lunch lady a
1,000 bill so you could buy lunch?
x 10
This is a REAL 1,000 billbut it has not been
printed since the early 1900s. The use of larger
bills was discontinued in 1969 because no one was
using them. For more information go to
www.moneyfactory.gov Click on collectors. There
actually are even bigger bills than this!
,
hundred dollars
thousand dollars
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Addition
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Solving the problem

• Put the first number on the top
• Put the second number on the bottom
• Line up the decimal points and all your place
  values
• Put the operation sign next to the bottom number
• Fill in each empty place value with a zero
• Add each column
• If you add and come up with a number bigger than
  9, then you have to cash in (carry).

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23.9 3.36 ____
first
second

23.9
3.36
Operation sign ( - x )
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23.9
0
What I have
3.36
0

What you have
27.26
.
2
7
6
2
What we have
12 dimes 1 dollar and 2 dimes. We need to keep
the 2 dimes and carry over the 1 dollar.
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Lets Practice
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3.9 14.67 _____
03.90
14.67
18.57
3
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4 8.63 _____
4.00
8.63
12.63
2
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3.9 14.67 1.01 _____
03.90
14.67
01.01
19.58
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