What is the fastest way to multiply a whole number by \(10\)?
Just add a zero to the end of the number. For example, to find \(10 \times 7\), you take the \(7\) and add a \(0\) to get \(70\).
Why does adding a zero work when you multiply by \(10\)?
Multiplying by \(10\) shifts every digit one place to the left in the place value chart. The ones place becomes the tens place, the tens becomes the hundreds, and so on. A zero is used as a placeholder in the now-empty ones place.
