We are about to count up 9 times starting from 9994(or 9 times by 100 starting from 999400).

Click to start counting. You can also do it step by step.

On the 6th count we encountered an overflow. The yellow light turned red and spawned another yellow light to the left, where we tried to count up again. No luck, another overflow. Then again and again. Finally, we found the place to rest the overflow token. Our attention returned to the initial position under the yellow light, where we found 3 more counts and performed them.