The code corresponds to the position of numbers in the alphabet: 1=A, 2=B, 3=C, so 4=D, 5=E, 6=F, thus 456 is DEF.

The code reverses the order of the numbers, so '456' becomes 'FED'.

'CAB' corresponds to '3', '1', '2' which is '321'.

'E' is the 5th letter in the alphabet, so it is coded as '5'.

The code is a reverse alphabet: H->S, E->V, L->O, L->O, O->L. Thus, HELLO is coded as SVOOL.

'D' corresponds to '4' in the same pattern.

'D' is the 4th letter in the alphabet, so it is coded as '4'.

The pattern is adding 3 to the letter. 'X' plus 3 is 'A'.

The pattern is shifting each letter forward by 3. 'C' corresponds to 'F'.

The pattern is that each letter is paired with its reverse in the alphabet. Thus, D corresponds to W.

The pattern is reversing the alphabet. 'X' corresponds to 'C'.

The pattern is reversing the alphabet, so 'C' corresponds to 'X'.

The pattern is reversing the alphabet. 'C' corresponds to 'X'.

Each letter is shifted by +1: C->D, I->J, R->S, C->D, L->M, E->F. Thus, SQUARE becomes TROFBS.

Each letter is shifted by +1, so 'APPLE' becomes 'BQQMF'.

Each letter is shifted by +1: M->N, O->P, U->T, S->T, E->F. Therefore, H->I, O->P, U->T, S->T, E->F, so HOUSE is coded as IPTVF.

Each letter in PEN is shifted by +1: P->Q, E->F, N->O. Thus, RAT becomes SBU.

Each letter is shifted forward by 1. 'B' to 'C', 'O' to 'P', 'O' to 'P', 'K' to 'L' gives 'CPPL'.

Each letter is shifted forward by 1. 'B' to 'C', 'A' to 'B', 'T' to 'U' gives 'CBU'.

Each letter is shifted by +1: R->S, A->B, T->U. Therefore, B->C, A->B, T->U, so BAT is coded as CBU.

Each letter is shifted forward by 1. 'C' to 'D', 'A' to 'B', 'T' to 'U' gives 'DBU'.

Each letter is shifted by +1: W->X, A->B, T->F, E->S, so F->G, I->J, R->S, E->F, thus FIRE is coded as GJTF.

'W' is the 4th letter from the end of the alphabet, so it is coded as '4'.

'XYZ' corresponds to '3', '2', '1' which is '123'.

The pattern is shifting forward in the alphabet. 'Z' corresponds to 'A'.

In the code, each letter corresponds to its position in the alphabet: C=3, A=1, T=20. Therefore, D=4, O=15, G=7, so DOG is 4157.

The code is the number of letters in the word plus the number of vowels. 'MOUSE' has 6 letters and 3 vowels, so 6 + 3 = 9.

The code is the number of letters in the word plus the number of vowels. 'MOUSE' has 6 letters and 3 vowels, so 6 + 3 = 9.

The code reverses the digits, so '456' becomes '654'.

The code reverses the order of the numbers: 1->A, 2->B, 3->C. Thus, 4->D, 5->E, 6->F, so 456 is FED.