diff --git a/640.md b/640.md
index 4b6e906..de059a4 100644
--- a/640.md
+++ b/640.md
@@ -105,7 +105,7 @@ The off command will switch off the motor and apply the brakes
 m1.off()
 ```
 
-##### setMotorSpeed()
+##### setMotorSpeed( *speed*)
 
 We can also stop the motor by using the second command and passing a speed of 0
 
@@ -206,7 +206,27 @@ stepper1 = dw.getStepper(1)
 
 #### Stepper motor control
 
+There are four commands for stepper motors. The first one you'll recognise
 
+##### off()
+
+The off command will switch off the stepper motor
+
+``` python
+stepper1.off()
+```
+
+##### setMotorSpeed( *rpm* )
+
+This command allows you to set the speed of your stepper motor. Pass the number of revolutions per minute that you want your stepper motor to run at.
+
+``` python
+stepper1.setMotorSpeed(200)
+```
+
+##### oneStep( *direction*, *style* )
+
+##### step( *steps*, *direction*, *style* )
 
 ## C++