From f19a77d06f98d7784c4a124d14023256acf73f88 Mon Sep 17 00:00:00 2001
From: Tanner Collin <git@tannercollin.com>
Date: Sat, 14 Mar 2026 14:19:23 -0600
Subject: [PATCH] fix: Dynamically calculate precision for scientific notation

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>
---
 calculator/calculator.app.js | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/calculator/calculator.app.js b/calculator/calculator.app.js
index 3fb39ed..81b19bc 100644
--- a/calculator/calculator.app.js
+++ b/calculator/calculator.app.js
@@ -286,7 +286,13 @@ function displayOutput(num) {
     }
     var numStr = num.toString();
     if (typeof num === 'number' && (numStr.length > RESULT_MAX_LEN || (num !== 0 && Math.abs(num) < 1e-4))) {
-        let precision = RESULT_MAX_LEN - 5;
+        // dynamic precision based on exponent length
+        var exp = Math.floor(Math.log(Math.abs(num)) / Math.LN10);
+        var expLen = String(Math.abs(exp)).length;
+        var signLen = (num < 0) ? 1 : 0;
+        // Total length is sign + first-digit + dot + fraction + E + exp-sign + exp-digits
+        // So precision for fraction is MAX - (sign + first-digit + dot + E + exp-sign + exp-digits)
+        let precision = RESULT_MAX_LEN - (signLen + 1 + 1 + 1 + 1 + expLen);
         if (precision < 0) precision = 0;
         num = toExponential(num, precision).replace("e", "E");
     } else {