Codon Wheel
A codon wheel is a very useful device for quickly translating DNA codons to amino acids.
To use wheel you start in the centre and work to the outside. So, if you had the codon CCT you would start at C in the centre, then move to the C in the next circle out, and then finally to the T in the last nucleotide base circle, the T. This would tell you that CCT is proline.
Another example is: