diff --git a/macros.asm b/macros.asm
index aa8876055..efd43318a 100644
--- a/macros.asm
+++ b/macros.asm
@@ -13,6 +13,8 @@ page   EQUS "db $50,"     ; Start a new Pokedex page.
 dex    EQUS "db $e8, $50" ; End a Pokedex entry.
 
 
+percent EQUS "* $ff / 100"
+
 ; macros require rst vectors to be defined
 FarCall    EQU $08
 Bankswitch EQU $10
@@ -118,15 +120,15 @@ B_ EQU 12
 
 
 bccoord: MACRO
-	ld bc, TileMap + SCREEN_WIDTH * \2 + \1
+	ld bc, TileMap + SCREEN_WIDTH * (\2) + (\1)
 	ENDM
 	
 decoord: MACRO
-	ld de, TileMap + SCREEN_WIDTH * \2 + \1
+	ld de, TileMap + SCREEN_WIDTH * (\2) + (\1)
 	ENDM
 
 hlcoord: MACRO
-	ld hl, TileMap + SCREEN_WIDTH * \2 + \1
+	ld hl, TileMap + SCREEN_WIDTH * (\2) + (\1)
 	ENDM