Skill: Decompose numbers in different ways

To decompose a number means to break it into parts that add to the same total. You can use hundreds, tens, and ones, or regroup some parts to make different addends.

Example: Decompose $(347)$ in different ways.

1. Start with the place-value parts:

   • $3$ hundreds $(=300)$
   • $4$ tens $(=40)$
   • $7$ ones $(=7)$

   So,

$$347=300+40+7$$

2. Regroup one ten as $(10)$ ones. Now there are $3$ tens and $(17)$ ones:

$$347=300+30+17$$

3. Regroup one hundred as $(100)$ ones. Now there are $2$ hundreds and $(147)$ ones:

$$347=200+147$$

Each way has the same total:

$$300+40+7=347$$ $$300+30+17=347$$ $$200+147=347$$

The parts change, but the whole number stays the same.