Displaying numbers larger than 9

Dear friends,
This is my problem statement:
"I have to prepare a vehicle, which is going to follow a straight line yellow path. Now, the path has some black strips randomly arranged on it. I have to display the no of black strips after finishing path."

Now, I have used a color sensor circuit. then i am planning to use BCD counter to count no of strips and using BCD to 7 seven segment decoder to display number. But if the no is larger than 9, counter resets after 0 to 9 to 0 again. How do i display the number if has multiple digits(say 2 digits)? do i have to join 2 counters?
Any help is welcome!

Yes, there should be a pulse genetated by the counter when it resets, just connect the to the input of your second counter. There's probably even an example on the datasheet of the IC you're using.

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Can you throw little more light on joining two counters?

74LS13X type chips have a carry and borrow output that can trigger a count on the next higher digit.

If you use TTL, which is the older technology, you put a jumper between output D from the 74LS90 (units counter) to input A from the next 7490 (decades counter).
These IC's will drive 74LS47 Ic's which drive the 7 segment displays.
With 2 cascaded together you can count up to 99.

Can't comment on the C MOS counter IC's because i have not built counters with them

What sort of ICs are you using?

Could you please post a schematic.?