In Class on Tues. 3/1 Amy introduced Decimals and Rational Numbers.When dealing with Decimals and Rational numbers you are to always keep in mind the place value of where the digits are located. A little tip to keep in mind is that any numbers to the right of the decimal point ALL have (ths) at the end of the place value.  Versus to the left having (ands,ed.etc)

Decimals: Any number written in base ten positional numeration can be called and considered a decimal
Rational Number:Any number that can be written in the form a/b, where b=/=0 and a and b are intergers, is what is called and considered rational numbers.Below is a link to a site to look into if you need additional help
http://cstl.syr.edu/fipse/decunit/opdec/opdec.htm

We learned how to write numbers in Expanded Notation for example
123.45= 1(100)+2(10)+3(1)+4(1/10)+5(1/100)
also in Exponential Notation
123.45= 1(10^2)+2(10^1)+3(10^0)+4(10^-1)+5(10^-2)

We also learned about place values.
Example 123.456
3 is in the ones place
4 is tenths place
5 is hundredths place
6 is in the thousandths place