Want To Blink 7 Segment Display In My Project

Hy Frnds here is the project in which i want to blink 7-segments. Any one knows how can I blink the 7 segment in this project , same like diwali bulbs it comes then go ,comes then go……. I used Encoder Inverter and decoder to display 0 to 9 digits one by one by using pull push buttons so what things i have to add in this project Which blink 7 segment.
My 2nd question is i used Decoder/driver (DM74LS47N) in this IC the pin 3 is LT, 4 is BI/RBO & 5 is RBI what is the purpose of these pins can i used these pins in this project??

Here is the pic of project:
https://i54.tinypic.com/28rjyxl.jpg

Yes, you can use pin 4 the BI / RBO pin. The attached circuit uses 1/3 of a 7404 Hex Inverter to do it but any pulse signals should work. The attached should blink the display about twice per second.

Ron

Simply put a flashing LED with buffer transistor on the common of the display.