🚧 Setup for 4.4

chapter_4/test_yourself.md

@@ -102,3 +102,33 @@ real number; not rational
 
 zero is an integer that is a ratio of integers where the denominator is not
 zero, $0 = \dfrac{0}{1}$.
+
+---
+
+**Test Yourself**
+
+Page 220
+
+1. To show that a nonzero integer $d$ divides an integer $n$, we must show that
+   ______.
+
+2. To say that $d$ divides $n$ means the same as saying that ______ is divisible
+   by ______.
+
+3. If $a$ and $b$ are positive integers and $a \mid b$, then ______ is less than
+   or equal to ______.
+
+4. For all integers $n$ and $d$, $d \nmid n$ if, and only if, ______.
+
+5. If $a$ and $b$ are integers, the notation $a \mid b$ denotes ______ and the
+   notation $a/b$ denotes ______.
+
+6. The transitivity of divisibility theorem says that for all integers $a$, $b$,
+   and $c$, if ______ then ______.
+
+7. The divisibility by a prime theorem says that every integer greater than $1$
+   is ______.
+
+8. The unique factorization of integers theorem says that any integer greater
+   than $1$ is either ______ or can be written as ______ in a way that is unique
+   except possibly for the ______ in which the numbers are written.