diff --git a/libs/microbit/core.d.ts b/libs/microbit/core.d.ts
index 59e0e1f7..0f7f7f96 100644
--- a/libs/microbit/core.d.ts
+++ b/libs/microbit/core.d.ts
@@ -153,6 +153,9 @@ declare interface Number {
     toString(): string;
 }
 
+/**
+ * Numbers and arithmetic operators
+ */
 declare namespace Math {
 
     /**