To find out how many lawns Gio needs to mow, we first need to determine how much more money he needs to save to reach his goal of $900.
- Current amount in bank account: $250
- Goal amount: $900
- Amount needed to reach the goal: \( 900 - 250 = 650 \)
Now, we know that Gio earns $25 for each lawn he mows. To find out how many lawns he needs to mow to earn the additional $650, we divide the amount needed by the earnings per lawn:
\[ \text{Number of lawns} = \frac{650}{25} = 26 \]
Therefore, Gio needs to mow 26 lawns to reach his savings goal of $900.