MATH NET
DECIMAL NUMBERS
SOFIA LOZANO
MARIA JOSE LAVERDE
LAURA JIMENEZ
GABRIELA CARDOZO.
DECIMAL NUMBERS
DEFINITION.
The word
"Decimal" means
"based on 10"
(From Latin
decima: a tenth
part).
"Decimal Number"
usually means
there is a Decimal
Point.
DECIMAL POINT
The decimal point is the most important part of a
Decimal Number. It is exactly to the right of the Units
position. Without it, we would be lost ... and not know
what each position meant.
The number to the left of the
decimal point is a whole
number and is 10x bigger.
The number to the right of the decimal
point is 10 times smaller and is a
decimal number. As we move further
right, every number place gets 10x
smaller.
OTHER DECIMAL NUMBERS
DEFINITIONS.
A linear array of
digits that represents
a real number, every
decimal place
indicating a multiple
of a negative power of
10.
 For example, the
decimal 0.1 = 1/10 ,
0.12 = 12/100 , 0.003 =
3/
1000 .

A DECIMAL NUMBER IS
ALSO CALLED DECIMAL
FRACTION:
A Decimal Fraction is a fraction where the
denominator (the bottom number) is a number
such as 10, 100, 1000, etc. (in other words a
power of ten) , the power depending on or
deciding the decimal place.
For example:
 the decimal 0.1 = 1/10 ,
 0.12 = 12/100 ,
 0.003 = 3/1000 .

QUESTIONS ABOUT
DECIMALS
•IS
DIFFERENT 0.3- 0.03?
• ANSWEAR: yes, because 0.03 is 10
times smaller than 0.3.
QUESTIONS ABOUT DECIMALS
Why 0.8 is bigger than 0.50?
 Answer:
First, you have to know that 0.50 = 0.5 .
Then, 0.8 is bigger than 0.5 because 0.8 = 8/10 or 8
parts of ten equal parts and 0.5 = 5/10 or 5 parts of
ten equal parts so 8 is greater than 5.

WRITING DECIMAL
NUMBERS
PROBLEM: write a decimal and a fraction
in simplest form for the part that is black.
Fraction :
12
100
Decimal:
0.12
DECIMAL IN DÓLLAR
1 cent = to 0.01
25 cents = 0.25
5 cents = 0.05
10 cents = 0.10
1 dollar = 1.00
50 cents = 0.50
5 dollars = 5.00
PROBLEM
Lina have to pay 43 dollars to buy her toy and she
have 100 dollars.
a. write this in a fraction and in decimal form.
b. How much money does she have left?
c. Can she buy with the money left another toy
that cost 64.50 dollars?
ANSWERS!
a. 43/100 = 0.43
b. 100 – 43 = 57 . She had left 57 dollars.
c. No she can’t buy the other toy because she
needs 7.5 dollars more.
USE OF
DECIMAL NUMBERS
To know about decimal numbers is
important because in daily life we
have to use like
money to buy things, in school for
science and math to find volume,
weight, etc. and to find the distance
between two places.
DECIMAL NUMBERS AND
DOLLARS




PROBLEM: I want to buy a candy bar for $0.75.
If I buy 4 candy bars, how much money will I
spend?
STRATEGY: Multiplication
PROCESS: $0.75
x4
----------$3.00
ANSWER: I will spend $ 3.00 dollars.
USE OF DECIMAL
NUMBERS
PROBLEM: In my neighborhood are 1,000
apartments and only 50 of them have balcony.
How can you write this information in fraction
and decimal numbers?
ANSWER:
• Fraction:
•
50
1000
Decimals: 0.005
USE OF DECIMAL
NUMBERS
PROBLEM: Mateo has with his name 4 colors of
100.
How can you write this information in fractions and
in decimals?
ANSWER:
o Fraction:
o
Decimal:
4
100
0.04
USE OF DECIMAL NUMBERS

The radio tower is 4.2 kilometers east of the
bakery. The gift shop is 14.2 kilometers east of
the bakery.
Which is closer to the radio tower, the gift shop or
the bakery?
a. gift shop
b. bakery
USE OF DECIMAL NUMBERS


In chemistry
laboratory we can
measure measuring
water volume using
both a ruler and a
graduated cylinder.
In this image the
volume of water is
70.3 ml.
USE OF DECIMAL NUMBERS
During science laboratory we can study various
physical properties of matter.
 Example: we can measure mass using a pan
balance to find the mass of a linking cube. Mass
could be of 3.6 grams.

BIBLIOGRAPHY
http://www.mathsisfun.com/decimals.htm
 http://www.google.com/imgres?imgurl
 http://www.kidsmathblog.com/wpcontent/uploads
 http://www.tutornext.com/help/decimals-tenthshundredths
 http://4cornerscce.blogspot.com/2010_11_01_archi
ve.html
