The mil cruzado (Cr$) is an obsolete Brazilian currency. Brazil has undergone several monetary reforms: the cruzado (1986-1989), cruzado novo (1989-1990), cruzeiro (1990-1993), cruzeiro real (1993-1994), and finally the real (BRL) in 1994, which remains the current currency.
At the 1989 transition (cruzado to cruzado novo), 1,000 cruzados = 1 cruzado novo. The cruzado novo was later pegged such that roughly 1,000 old cruzados ≈ 1 USD at that time. However, this is purely historical.
Today, the real trades around 5.38 BRL = 1 USD (rate varies). Old cruzados have no monetary value and cannot be exchanged. They are collectors' items only. For current conversions, use BRL/USD rates from a reliable financial source.