converters

i want to design a converter that converts BCD to seven segmental display?
How can i do this?

Make a table that shows which segments are illuminated for each BCD code. That will be your guide for the logic in the converter.

i have made it but was unable to understand what should i do for numbers above 9 .should i use the don't care condition

BCD is binary coded decimal. It encompasses only 0-9. You only need those digits.

in BCD we have 4-bit representation.0-9 can be represented and interms of zeros and ones.when i form a karnauge map i will have 16 position.i will be able to fill 10 of them by 0 and 1 according to BCD conversions for each element of seven segmental display.what about the other positions?

If you are interested in BCD, just ignore them.