# math

posted by
**morgan2** on
.

I am trying to convert km to meters, centimeters and milimeters. Some of the orignals are like 1.5 km= ?m or cm or mm. I am really having a hard time getting the decimal points in the right place or when to leave them out altogether. I'm only in 5th grade. HELP!

Here is an easy way to do it. Here are the first six prefixes.

kilo

hecto

deca

unit as length, volume, second, etc.

deci

centi

milli

Here is what you do. Start somewhere on the scale above. Move the decimal point to the left if we go UP the scale and to the right if we go DOWN the scale. For example,

4.5 meter = ?? kilometers.

We start at the unit position. We move 1 to deca, 1 to hecto and 1 to kilo for 3 total. So move the decimal point three places to the left and 4.5 m = 0.0045 km.

Or 0.0045 km = ?? millimeters.

Start at km, we move 1 to hecto, 1 to deca, 1 to unit, 1 to deci, 1 to centi and 1 to milli or 6 places total. So move the decimal 6 places to the right.

0.0045 km = 4500 mm. I hope this helps. There are other prefixes but those can come later.

Thank you!!!! That little light went on in an instant! My Mom thanks you too, even she understands it now!