diff --git a/docs/sph4u7.md b/docs/sph4u7.md
index 9b3bfa0..cbf842d 100644
--- a/docs/sph4u7.md
+++ b/docs/sph4u7.md
@@ -551,9 +551,9 @@ $$
 Space is also relative. An observer moving at a higher constant velocity will have space contract — this phenomenon is known as **length contraction**.
 
 Where $L_s$ is the length/distance measured of an object at the same location and at rest relative to a stationary observer, and $L_m$ is the length/distance from a different reference frame:
-$$L_m=\gamma L_s$$
+$$L_m=\frac{\gamma}{L_s}$$
 
-From different inertial reference points, there can never be agreement on whether events are simultaneous. Because time slows down for an obserer moving faster, one event will also appear to happen first.
+From different inertial reference points, there can never be agreement on whether events are simultaneous. Because time slows down for an observer moving faster, one event will also appear to happen first.
 
 ## Resources