We reviewed a bit of our divisibility rules today in class. As an intelligent parent mentioned... Technically all numbers are divisible by all numbers, but they often result in yucky, long decimal values. When I talk about "divisible" I mean EVENLY divisible. :)

We completed the large wall Venn Diagram in class today. A big thanks to my Green class that put ALL of the numbers in the Venn Diagram...

OR THE BOX OF SHAME!

We also began to learn about Prime numbers...

We used the Sieve of Eratosthenes to identify the primes from 1-400. Try it yourself on

this page.

Want some practice learning about Prime and Composite numbers? Check out

this tutorial from Math is fun.

No actual homework this weekend, but we will have a

quiz on September 23rd. I handed out a study guide in class, but it seems like a few people left it behind... Read below to see what you might have forgotten to bring home!

*You are
responsible for the following information for this quiz:*

1) __Divisibility
Rules__ - you will be given a number and must be able to determine
whether it is divisible by 2, 3, 5, or 10 using a Venn Diagram.

For example: 56,340

(You would place the number in
the correct space on the Venn Diagram)

***You must have the
divisibility rules memorized***

2) __Prime
and Composite Numbers__ - you must know the definitions of prime and
composite numbers

*Prime
Numbers* - the only factors of a prime number are 1 and itself

*Composite
Numbers* - Composite numbers have *other
factors* besides 1 and itself

You
must also be able to sort a list of numbers in two groups: prime & composite

3) __Probability
& Ratio__

You
must know how to write a ratio in lowest terms and find the probability of an
event as a fraction in lowest terms.

For
example ~ Probability: A junk box
contains 5 markers, 6 pom-poms, and 3 beads.
What is the probability of picking a marker from the box without
looking? __Answer: 5 out of 14__

Ratio: What is the ratio of pom-poms to
markers? __Answer: 6:5 or 6 to 5 or __ __6__

** 5**

4) __Percent__

You
must be able to identify the percent when given a fraction or ratio.

For
example: A junk box contains 10 markers, 6 pom-poms, and 4 beads. What percent of the pom-poms is in the
box? __Answer:__ __6__ __30
__ = 30%
** **__20
100__

See you all on Monday! Have a great weekend!

-Miss K :)