The number 31,006,150 written out in words is thirty-one million six thousand one hundred and fifty. Every number has a place value, whether it be a million, a thousand, or just one.
The ones place (1) is one step right from the decimal place. The tens place (10) is one step right from there. From then on, the numbers get larger. Next comes the hundreds (100). After this, the numbers follow this same pattern: ones, tens, then hundreds. This is why numbers are organized in sets of three. One step right from the hundreds is the thousands (1,000), followed by the ten thousands (10,000), and hundred thousands (100,000). Then comes the millions (1,000,000), ten millions (10,000,000) and hundred millions (1000,000,000).
Numbers keep going on forever, getting larger and larger as they move one step to the right. If you can remember these number places, the next step is simply plugging the written numbers into the right places. For example, nine hundred million seven hundred sixty-five thousand two hundred and eighty-five is written as 900,765,285. You simply put the numbers in their places.