The big picture
Here are the eleven ideas, in order.
| Idea | Remember |
|---|---|
| Times ten | Each digit moves one column left per zero. Fill gaps with 0. |
| Share into ten | The same move the other way. Open new columns if needed. |
| Times a whole number | Multiply the digits. Then put the point back. |
| Times another decimal | Multiply the digits. Add the two place counts. |
| Which way it moves | Below 1 shrinks a number above 0. Above 1 grows it. At 1 nothing moves. |
| Sharing it out | Left to right. A leftover becomes ten of the next part. |
| The other name | Make the bottom 10, 100 or 1000, if some number can. The top gives the digits. The bottom sets the point. |
| Rates | A rate times an amount gives the bill. |
| Divide by a decimal | Multiply both numbers by the same 10, 100 or 1000. The answer does not change. |
| Divide by less than 1 | A divisor below 1 makes a number above 0 grow. Above 1 it shrinks. |
| Never-ending sharing | Either a remainder is 0 and the division ends. Or one comes back and the digits repeat. |
Your book's Part II, Chapter 4 is Another Peek Beyond the Point. Go and open it.