Easy.
Your number would be 2,222 and you'd circle the first 2 (starting from the left) and underline the last 2(again, starting from the left).
The reason why you'd underline the last 2, is because the very last number would represent the ones place. The first 2 would be the thousands place. Meaning that 2,222 would translate to two-thousand two-hundred twenty-two.