Get items appearing on the sheet, still a lot to do but this is a strong step in the right direction

module/utils/roundToPrecision.mjs

@@ -0,0 +1,20 @@
+/**
+ * Takes a possibly-decimal value and rounds after a certain precision, keeping
+ * only the specified amount of decimals.
+ *
+ * @param {number} value The value that is to be rounded.
+ * @param {number} precision The number of decimal places to round to. Must be a
+ * positive integer.
+ * @returns The rounded number
+ */
+export function toPrecision(value, precision = 1) {
+	if (!Number.isInteger(precision)) {
+		throw `Precision must be an integer`;
+	};
+	if (precision < 0) {
+		throw `Precision must be greater than or equal to 0`;
+	};
+
+	const m = 10 ** precision;
+	return Math.round(value * m) / m;
+};