Use a colon instead of comma

pages/common/dc.md

@@ -14,6 +14,6 @@
 
 `echo "7 k 5 _3 / p" | dc`
 
-- To 100 decimal places [100 k], calculate the golden ratio, phi, sqrt(5) [5 v] plus 1 [1 +], divided by 2 [2 /], and [p]rint result:
+- To 100 decimal places [100 k], calculate the golden ratio, phi: sqrt(5) [5 v] plus 1 [1 +], divided by 2 [2 /], and [p]rint result:
 
 `echo "100 k 5 v 1 + 2 / p" | dc`