Composing Numbers

Composing
So 349 is composed of 3 hundreds, 4 tens and 9 ones, in other words:

300 + 40 + 9  ⇒  349 "Composing"

Example: Compose 2 hundreds, 7 tens and 9 ones.
200 + 70 + 9 = 279

Decomposing
Decomposing is when we break the number apart:

349  ⇒  300 + 40 + 9 "Decomposing"

Example: Decompose 3.456
3.456 = 3.000 + 400 + 50 + 6

Standard and Expanded Form
Some people call the two different forms "Standard" and "Expanded":

Example: Put 925 into Expanded Form
925 = 900 + 20 + 5

Decimal Numbers
We can also compose and decompose decimal numbers:

37,2  ⇒  30 + 7 + 0,2 "Decomposing"

4 + 0,7 + 0,08  ⇒  4,78 "Composing"

Example: Decompose 1,35
1,35 = 1 + 0,3 + 0,05