When does a new number family start?

When counting by powers of ten, a new family starts every multiple of 3. 10^3 is the start of the thousands family, 10^6 is the start of the millions family, 10^9 is the start of the billions family, 10^12 the start of the trillions family. Within the family, the next two powers of ten are for the tens and the hundreds. For example, 10^7 is ten millions and 10^8 is hundred millions. As your student what 10^10 is: ten billions