If TOUR is written as 1234, CLEAR is written as 56784 and SPARE is written as…

In a letter-to-number coding-decoding puzzle, each letter of the alphabet is assigned one fixed digit throughout the puzzle. When several coded words are given, letters that repeat across two or more words act as anchors — the same letter must map to the same digit in every word, so cross-checking the overlapping letters verifies the mapping before it is applied to a new word.

1. TOUR → 1234 gives the single-letter mapping T=1, O=2, U=3, R=4.

2. CLEAR → 56784: matching each letter of CLEAR (C, L, E, A, R) to each digit (5, 6, 7, 8, 4) in order gives C=5, L=6, E=7, A=8, R=4 — the R=4 here matches R=4 from TOUR, confirming the mapping so far.

3. SPARE → 90847: matching each letter of SPARE (S, P, A, R, E) to each digit (9, 0, 8, 4, 7) in order gives S=9, P=0, A=8, R=4, E=7 — the A, R and E digits here match exactly the A, R, E digits already found from CLEAR.

4. CARE uses the letters C, A, R, E, whose digits are already fixed: C=5, A=8, R=4, E=7 — reading them in the letter order of CARE gives the code 5847.

Because R appears in both TOUR and CLEAR and gives the digit 4 both times, and A, R, E each appear in both CLEAR and SPARE giving matching digits (A=8, R=4, E=7) in both, the full mapping is internally consistent — reconstructing CARE from either CLEAR's or SPARE's overlapping letters independently confirms the same code.