When a number is made up of more than one digit we ... representing 11. Adding up the ones column first we can see there are 9 ones in total. In the tens column there are 2 tens.

In the third line we are multiplying by \(300\) (three hundreds). As we are multiplying by hundreds both the tens and unit digit will ... times3=9\): add the carried \(2\) to get \(11\), put ...