To balance a chemical equation step by step, follow these easy steps:

1. Write the Unbalanced Equation:
   First, figure out what you have and what you’re making. For example:
   $\text{C}_3\text{H}_8 + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O}$

2. Count Atoms:
   Next, count how many atoms there are for each element on both sides:

   • On the left side: C: 3, H: 8, O: 2
   • On the right side: C: 1, H: 2, O: 3

3. Balance the Elements:
   Now, let's make the sides equal. Start with the metals, then nonmetals, and finish with oxygen and hydrogen:

   • To balance carbon (C), add a 3 in front of the $\text{CO}_2$:
     $\text{C}_3\text{H}_8 + \text{O}_2 \rightarrow 3\text{CO}_2 + \text{H}_2\text{O}$

4. Adjust for Hydrogen:
   Next, balance the hydrogen (H) by adding a 4 in front of $\text{H}_2\text{O}$:
   $\text{C}_3\text{H}_8 + \text{O}_2 \rightarrow 3\text{CO}_2 + 4\text{H}_2\text{O}$

5. Balance Oxygen Last:
   Finally, count the oxygen (O) again and adjust it if needed. This leads to:
   $\text{C}_3\text{H}_8 + 5\text{O}_2 \rightarrow 3\text{CO}_2 + 4\text{H}_2\text{O}$

Now, let’s check our final counts to make sure everything is balanced:

• C: 3, H: 8, O: 10 on both sides.

And that’s it! You’ve balanced the equation!