Five points, four jumps

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#diagnosis p,.strip{overflow-wrap:anywhere}</style></head><body><main><header><p class="kicker">NUMBER PATHS · START + STEP × JUMPS</p><h1>Five points, four jumps</h1><p>Read the supplied rule. Index0 is the start; index4 follows four jumps. Explain the gap as well as the answer.</p></header><div class="actions"><button type="button" id="rule1">SC1</button><button type="button" id="rule2">SC2</button><button type="button" id="rule3">SC3</button></div><section class="panel"><h2>Stated rule</h2><div id="rule" class="result" role="status" aria-live="polite"></div><div id="path" class="strip"></div><p>Indexes0 → 1 → 2 → 3 → 4. Equal gaps represent the stated equal increments.</p></section><section class="panel"><h2>Complete and explain</h2><label for="missing">Missing value at index2</label><input id="missing" type="text" value=""><label for="finalValue">Final value after4 jumps</label><input id="finalValue" type="text" value=""><div id="diagnosis"><p>SC1 wrong path:46 → 56 → 67 → 77 → 87. Gaps: 1 = 46→56; 2 = 56→67; 3 = 67→77; 4 = 77→87.</p><label for="gap">First violating gap number1–4</label><input id="gap" type="text" value=""></div><label for="reason">Why does your answer fit the stated rule?</label><textarea id="reason" rows="4"></textarea><div class="actions"><button type="button" id="check">Check fixed answers</button><button type="button" id="reveal">Reveal explanation key</button><button type="button" id="reset">Clear this rule</button></div><div id="feedback" class="result" role="status" aria-live="polite">Answers begin blank.</div><div id="key" class="strip" hidden></div></section><footer>Five points contain four jumps. Repair the first wrong gap, then recompute the points after it.</footer><noscript>JavaScript is required for the local controls. The accompanying article contains worked examples.</noscript></main><script>
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