diff --git a/docs/objects.md b/docs/objects.md
index 7f4e4d5..d830152 100644
--- a/docs/objects.md
+++ b/docs/objects.md
@@ -95,6 +95,7 @@ that are called on special operators.
 | __newindex   | `(<object>, key, newValue)`                      | Called on new index using the '[] = ' operator              |
 | __index      | `(<object>, key)` -> `value`                     | Called on index using the '[]' operator                     |
 | __tostring   | `(<object>)` -> `<string>`                       | Called when tostring() is called on an object               |
+| __tonumber   | `(<object>)` -> `<number>`                       | Called when tonumber() is called on an object               |
 | __count      | `(<object>)` -> `<number>`                       | Called when object is used with the '#' count operator      |
 | __iter       | `(<object>)` -> `<object>`                       | Called when used in a for-each loop with the 'in' operator  |
 | __next       | `(<object>)` -> `...`                            | Called on each iteration in a for-each loop, return values are passed as parameters in the loop |
diff --git a/src/cobj.c b/src/cobj.c
index 446b183..b499438 100644
--- a/src/cobj.c
+++ b/src/cobj.c
@@ -462,6 +462,26 @@ CObjString *cosmoO_toString(CState *state, CObj *obj) {
 }
 
 cosmo_Number cosmoO_toNumber(CState *state, CObj *obj) {
+    CObjObject *proto = cosmoO_grabProto(obj);
+    CValue res;
+
+    if (proto != NULL && cosmoO_getIString(state, proto, ISTRING_TONUMBER, &res)) {
+        cosmoV_pushValue(state, res);
+        cosmoV_pushValue(state, cosmoV_newObj(obj));
+        if (cosmoV_call(state, 1, 1) != COSMOVM_OK) // call res, expect 1 return val of <number>
+            return 0;
+        
+        StkPtr temp = cosmoV_getTop(state, 0);
+        if (!IS_NUMBER(*temp)) {
+            cosmoV_error(state, "__tonumber expected to return <number>, got %s!", cosmoV_typeStr(*temp));
+            return 0;
+        }
+
+        // return number
+        cosmoV_pop(state);
+        return cosmoV_readNumber(*temp);
+    }
+
     switch (obj->type) {
         case COBJ_STRING: {
             CObjString *str = (CObjString*)obj;
@@ -479,7 +499,7 @@ int cosmoO_count(CState *state, CObj *obj) {
     if (proto != NULL && cosmoO_getIString(state, proto, ISTRING_COUNT, &res)) {
         cosmoV_pushValue(state, res);
         cosmoV_pushValue(state, cosmoV_newObj(obj));
-        if (!cosmoV_call(state, 1, 1) != COSMOVM_OK) // call ret, we expect 1 return value of type <number>
+        if (cosmoV_call(state, 1, 1) != COSMOVM_OK) // call res, we expect 1 return value of type <number>
             return 0;
 
         StkPtr ret = cosmoV_getTop(state, 0);
diff --git a/src/cstate.c b/src/cstate.c
index 40367a5..47697b2 100644
--- a/src/cstate.c
+++ b/src/cstate.c
@@ -24,7 +24,7 @@ CState *cosmoV_newState() {
     state->grayStack.count = 0;
     state->grayStack.capacity = 2;
     state->grayStack.array = NULL;
-    state->allocatedBytes = 0;
+    state->allocatedBytes = sizeof(CState);
     state->nextGC = 1024 * 8; // threshhold starts at 8kb
 
     // init stack
@@ -42,12 +42,13 @@ CState *cosmoV_newState() {
     for (int i = 0; i < ISTRING_MAX; i++)
         state->iStrings[i] = NULL;
 
-    cosmoT_initTable(state, &state->strings, 8); // init string table
+    cosmoT_initTable(state, &state->strings, 16); // init string table
     cosmoT_initTable(state, &state->globals, 8); // init global table
 
     // setup all strings used by the VM
     state->iStrings[ISTRING_INIT] = cosmoO_copyString(state, "__init", 6);
     state->iStrings[ISTRING_TOSTRING] = cosmoO_copyString(state, "__tostring", 10);
+    state->iStrings[ISTRING_TONUMBER] = cosmoO_copyString(state, "__tonumber", 10);
     state->iStrings[ISTRING_INDEX] = cosmoO_copyString(state, "__index", 7);
     state->iStrings[ISTRING_NEWINDEX] = cosmoO_copyString(state, "__newindex", 10);
     state->iStrings[ISTRING_COUNT] = cosmoO_copyString(state, "__count", 7);
diff --git a/src/cstate.h b/src/cstate.h
index 82f1797..d3df773 100644
--- a/src/cstate.h
+++ b/src/cstate.h
@@ -15,6 +15,7 @@ typedef struct CCallFrame {
 typedef enum IStringEnum {
     ISTRING_INIT,       // __init
     ISTRING_TOSTRING,   // __tostring
+    ISTRING_TONUMBER,   // __tonumber
     ISTRING_INDEX,      // __index
     ISTRING_NEWINDEX,   // __newindex
     ISTRING_COUNT,      // __count