Commutative property fails?

I will attempt to prove that $\frac00 = 1$. In which of these steps did I first make a mistake by using flawed logic?

Step 1: We can rewrite 15 as $7 + 8$ or $8 + 7$.
Step 2: This means that $7 + 8 = 8+ 7$.
Step 3: If we move one term from each side of the equation to the other side, we will get $7-7 = 8-8.$
Step 4: Dividing both sides by $8-8$ gives $\frac{7-7}{8-8} = 1$.
Step 5: Since $7-7= 0$ and $8-8 = 0$, $\frac00 = 1$.