diff --git a/doc/site/core/num.markdown b/doc/site/core/num.markdown
index a3f93bc5..42504c4d 100644
--- a/doc/site/core/num.markdown
+++ b/doc/site/core/num.markdown
@@ -8,6 +8,23 @@ The absolute value of the number.
     :::dart
     -123.abs // 123
 
+### **acos**
+
+The arc cosine of the number.
+
+### **asin**
+
+The arc sine of the number.
+
+### **atan**
+
+The arc tangent of the number.
+
+### **atan**(x)
+
+The arc tangent of the number when divided by `x`, using the signs of the two
+numbers to determine the quadrant of the result.
+
 ### **ceil**
 
 Rounds the number up to the nearest integer.
@@ -42,6 +59,10 @@ The sine of the number.
 
 The square root of the number. Returns `nan` if the number is negative.
 
+### **tan**
+
+The tangent of the number.
+
 ### **-** operator
 
 Negates the number.
@@ -118,3 +139,6 @@ Attempts to parse `value` as a decimal literal and return it as an instance of
 
 It is a runtime error if `value` is not a string.
 
+### Num.**pi**
+
+The value of π.
diff --git a/src/vm/wren_core.c b/src/vm/wren_core.c
index 84083258..580587ba 100644
--- a/src/vm/wren_core.c
+++ b/src/vm/wren_core.c
@@ -907,6 +907,26 @@ DEF_PRIMITIVE(num_abs)
   RETURN_NUM(fabs(AS_NUM(args[0])));
 }
 
+DEF_PRIMITIVE(num_acos)
+{
+  RETURN_NUM(acos(AS_NUM(args[0])));
+}
+
+DEF_PRIMITIVE(num_asin)
+{
+  RETURN_NUM(asin(AS_NUM(args[0])));
+}
+
+DEF_PRIMITIVE(num_atan)
+{
+  RETURN_NUM(atan(AS_NUM(args[0])));
+}
+
+DEF_PRIMITIVE(num_atan2)
+{
+  RETURN_NUM(atan2(AS_NUM(args[0]), AS_NUM(args[1])));
+}
+
 DEF_PRIMITIVE(num_ceil)
 {
   RETURN_NUM(ceil(AS_NUM(args[0])));
@@ -960,6 +980,11 @@ DEF_PRIMITIVE(num_sqrt)
   RETURN_NUM(sqrt(AS_NUM(args[0])));
 }
 
+DEF_PRIMITIVE(num_tan)
+{
+  RETURN_NUM(tan(AS_NUM(args[0])));
+}
+
 DEF_PRIMITIVE(num_toString)
 {
   RETURN_VAL(wrenNumToString(vm, AS_NUM(args[0])));
@@ -1006,6 +1031,11 @@ DEF_PRIMITIVE(num_negate)
   RETURN_NUM(-AS_NUM(args[0]));
 }
 
+DEF_PRIMITIVE(num_pi)
+{
+  RETURN_NUM(3.14159265358979323846);
+}
+
 DEF_PRIMITIVE(num_minus)
 {
   if (!validateNum(vm, args, 1, "Right operand")) return PRIM_ERROR;
@@ -1544,6 +1574,7 @@ void wrenInitializeCore(WrenVM* vm)
 
   vm->numClass = defineClass(vm, "Num");
   PRIMITIVE(vm->numClass->obj.classObj, "fromString(_)", num_fromString);
+  PRIMITIVE(vm->numClass->obj.classObj, "pi", num_pi);
   PRIMITIVE(vm->numClass, "-", num_negate);
   PRIMITIVE(vm->numClass, "-(_)", num_minus);
   PRIMITIVE(vm->numClass, "+(_)", num_plus);
@@ -1563,6 +1594,10 @@ void wrenInitializeCore(WrenVM* vm)
   PRIMITIVE(vm->numClass, "..(_)", num_dotDot);
   PRIMITIVE(vm->numClass, "...(_)", num_dotDotDot);
   PRIMITIVE(vm->numClass, "abs", num_abs);
+  PRIMITIVE(vm->numClass, "acos", num_acos);
+  PRIMITIVE(vm->numClass, "asin", num_asin);
+  PRIMITIVE(vm->numClass, "atan", num_atan);
+  PRIMITIVE(vm->numClass, "atan(_)", num_atan2);
   PRIMITIVE(vm->numClass, "ceil", num_ceil);
   PRIMITIVE(vm->numClass, "cos", num_cos);
   PRIMITIVE(vm->numClass, "floor", num_floor);
@@ -1571,6 +1606,7 @@ void wrenInitializeCore(WrenVM* vm)
   PRIMITIVE(vm->numClass, "sign", num_sign);
   PRIMITIVE(vm->numClass, "sin", num_sin);
   PRIMITIVE(vm->numClass, "sqrt", num_sqrt);
+  PRIMITIVE(vm->numClass, "tan", num_tan);
   PRIMITIVE(vm->numClass, "toString", num_toString);
   PRIMITIVE(vm->numClass, "truncate", num_truncate);
 
diff --git a/test/core/number/acos.wren b/test/core/number/acos.wren
new file mode 100644
index 00000000..54d54da9
--- /dev/null
+++ b/test/core/number/acos.wren
@@ -0,0 +1,3 @@
+IO.print(0.acos)        // expect: 1.5707963267949
+IO.print(1.acos)        // expect: 0
+IO.print((-1).acos)     // expect: 3.1415926535898
diff --git a/test/core/number/asin.wren b/test/core/number/asin.wren
new file mode 100644
index 00000000..e6c312af
--- /dev/null
+++ b/test/core/number/asin.wren
@@ -0,0 +1,3 @@
+IO.print(0.asin)        // expect: 0
+IO.print(1.asin)        // expect: 1.5707963267949
+IO.print((-1).asin)     // expect: -1.5707963267949
diff --git a/test/core/number/atan.wren b/test/core/number/atan.wren
new file mode 100644
index 00000000..822315d7
--- /dev/null
+++ b/test/core/number/atan.wren
@@ -0,0 +1,2 @@
+IO.print(0.atan)        // expect: 0
+IO.print(1.atan)        // expect: 0.78539816339745
diff --git a/test/core/number/atan2.wren b/test/core/number/atan2.wren
new file mode 100644
index 00000000..e1f5289f
--- /dev/null
+++ b/test/core/number/atan2.wren
@@ -0,0 +1,4 @@
+IO.print(0.atan(0))     // expect: 0
+IO.print(0.atan(1))     // expect: 0
+
+IO.print(1.atan(0))     // expect: 1.5707963267949
diff --git a/test/core/number/cos.wren b/test/core/number/cos.wren
new file mode 100644
index 00000000..b7be49af
--- /dev/null
+++ b/test/core/number/cos.wren
@@ -0,0 +1,6 @@
+IO.print(0.cos)             // expect: 1
+IO.print(Num.pi.cos)        // expect: -1
+IO.print((2 * Num.pi).cos)  // expect: 1
+
+// this should of course be 0, but it's not that precise
+IO.print((Num.pi / 2).cos)  // expect: 6.1232339957368e-17
diff --git a/test/core/number/sin.wren b/test/core/number/sin.wren
new file mode 100644
index 00000000..da2218e9
--- /dev/null
+++ b/test/core/number/sin.wren
@@ -0,0 +1,6 @@
+IO.print(0.sin)             // expect: 0
+IO.print((Num.pi / 2).sin)  // expect: 1
+
+// these should of course be 0, but it's not that precise
+IO.print(Num.pi.sin)        // expect: 1.2246467991474e-16
+IO.print((2 * Num.pi).sin)  // expect: -2.4492935982947e-16
diff --git a/test/core/number/tan.wren b/test/core/number/tan.wren
new file mode 100644
index 00000000..7173db4b
--- /dev/null
+++ b/test/core/number/tan.wren
@@ -0,0 +1,3 @@
+IO.print(0.tan)             // expect: 0
+IO.print((Num.pi / 4).tan)  // expect: 1
+IO.print((-Num.pi / 4).tan) // expect: -1