Jason intended to fry 550 fish-balls.<br>
He fried 470 in the morning.<br><br>
&bull; Remaining = Total &minus; Fried<br>
&bull; = 550 &minus; 470 = 80<br>
<br>
Jason has to fry 80 more fish-balls.<br>
Check: 470 + 80 = 550. ✓