Why 06 is added to daa instruction in 8085?

The DAA (Decimal Adjust Accumulator) instruction in the 8085 conditionally adds 06H to A in order to normalize the low order nibble to a BCD value betwen 0H and 9H. It then conditionally adds 60H to A in order to similarly normalize the high order nibble.

This is done as part of supporting multi-precision decimal arithmetic.