In D2L->Content->Readings, read the article "Investigating Students' Conceptual Understanding of Decimal Fractions Using Multiple Representations"

Decimals and place value.
Misconceptions and representations part 1; part 2.
Decimals in metric measurements.
Decimals on number lines.

a. in a grid
b. with base 10 blocks
c. on a number line. 
d. tell what length in centimeters or millimeters each represents if 1 means 1 m. (tell, don't draw)

D2L->Content->Readings->Relating Fractions and Decimals

More misconceptions
Using a grid to convert fractions to decimals involves using a decimal grid, subdividing it into the appropriate fraction and then using the original grid to figure out the decimal representation for the amount.
Using division to convert fractions to decimals

Assn 62: Converting fractions and decimals.

D2L->Content->Readings->The Finger and the Moon
Reference on significant digits

Explaining addition (and an extra example--very optional)
The difficulties of multiplication
An invented algorithm part 1, part 2.
Decimal multiplication with arrays part 1, part 2.
Things to know before you start dividing decimals: ways to handle remainders; significant digits.
Dividing decimals part 1, part 2;
And an optional ramble on remainders and dividing decimals.

Assn 63: Decimal operations.