diff --git a/math/number_theory/notes.page b/math/number_theory/notes.page
index c98857c..211e4d5 100644
--- a/math/number_theory/notes.page
+++ b/math/number_theory/notes.page
@@ -55,9 +55,9 @@ For all $a$, $1\mid a$ and $a\mid a$; For non-zero $b$, $b\mid 0$.
 
 When $c\neq0$:
 $$\begin{align}
-b\mid a . c\mid b &\to c\mid a\\
+b\mid a \cdot c\mid b &\to c\mid a\\
 b\mid a &\to bc\mid ac\\
 \end{align}$$
 and
-$$c\mid a . c\mid b \to c\mid ma + nb$$
+$$c\mid a \cdot c\mid b \to c\mid ma + nb$$
 for all integers $m$ and $n$