Pi Day: March 14th

Pi Day-- What a fabulous irrational day!!

CHECK OUT THE PICTURES

Today we celebrated Π (Pi), a very cool number. Π is a comparison between the measurements of the circumference to the diameter of a circle—any circle. Pi is an IRRATIONAL number. That means it has no pattern and never terminates. It CANNOT be written as a fraction with an integer in the numerator and denominator. We use 3.14 and 22/7 as APPROXIMATIONS of pi. These are not the exact values. The only symbol that tells the exact value is Π. Pi is a ratio, a comparison between two numbers. You will be able to discover many interesting facts about pi—even finding it on your own.

Think about your results and answer these questions:

How does the measurement of the circumference compare to the measurement of the diameter? Is it twice as large? Is it three times as large or more than three times as large?

Are you values of pi consistent? Explain why or why not?


What reasons do you think would account for these differences?

On your computer, read about the history of pi at this website

http://ualr.edu/lasmoller/pi.html

Record 5 new or interesting facts about pi that you learned

Part 2 – Finding Yourself in Pi

Pi is an irrational number. That means that it is a non-terminating, non-repeating decimal. Since the number order keeps changing you will eventually find any group of numbers in a sequence, somewhere in the never-ending list. Through the influence of high speed computers that can process large amounts of data, we can examine this aspect of pi much more easily. There are even websites that will instantly search pi for any string of numbers.

Your assignment is to locate a specific string of numbers in pi. Pick a string of 7 or more numbers that is meaningful or significant to you, such as your phone number or birthday (for example: if your birthday is February 9, 1993, then your number string would be 02091993). On your computer, use the Pi Searcher at http://www.angio.net/pi/piquery to find where in pi your number string occurs. Record the string of numbers and what position it holds in the list of numbers.

My number string__________________

Position in pi________________

Pre Algebra Periods 1, 2, & 4

Percent Problems 6-6 and 6-7:

2 METHODS: EQUATION AND PROPORTION

EQUATION METHOD:
Just TRANSLATE and SOLVE for the missing number
Remember: OF = MULTIPLY!

EXAMPLE:
What percent of 25 is 13?

first put the = sign under the word is

What represents the variable-- the unknown

where you see of use ( )

p 25 = 13 but rewrite as

25p = 13, so p = .52 or 52%

EXAMPLE:
Find 60% of 15
.6(15) = 9

EXAMPLE:
35% of what number is 52.5
.35n = 52.5 so n = 150

PROPORTION METHOD

% thth the"is"
-------- = ---------
100 theh "of"

Substitute what you know, solve for what you don't know.
ALWAYS LOOK TO SEE IF YOU HAVE THE % FIRST BECAUSE IT'S THE EASIEST!
Next, see if you have "of"

Pre Algebra Periods 1, 2, & 4

Fractions = Decimals=Percents 6 -5
% literally means "out of 100" and
the symbol comes from the fraction bar and a denominator of 100

**TO CHANGE ANY % TO A FRACTION:
Simply get rid of the % sign and put the number over a denominator of 100. Simplify (reduce).
EX: 5% = 5/100 = 1/20

**TO CHANGE ANY % TO A DECIMAL:
Simply get rid of the % and move the decimal point over to the LEFT 2 PLACES (run AWAY from the %)
EX: 5% = .05

**TO CHANGE ANY DECIMAL TO A %
Simply put the % to the right of the number and move the decimal point to the RIGHT 2 PLACES (run towards the %)
EX: .245 = 24.5%

**TO CHANGE ANY FRACTION TO A %
Simply change it to a decimal first, then to a % as above
EX: 20/50 = .4 = 40%
or
If the denominator will go into 100 easily, you can use equivalent fractions
EX: 20/50 The denominator goes into 100 easily, so just multiply by 2 and get 40/100 = 40%

If you ever forget how many places to move the decimal,
just look at the % sign - It tells you 2 places (2 zeros!)