Engaging and educational – Subtracting Sardines HD Review

I love adding apples and when I started a subtraction unit I was excited to see Subtracting Sardines. It's a very simple concept but kids will play for hours. My only problem is that it allows kids to take away a larger number than they started with. Red sardines appear and the answer is a negative number. For a visual approach this doesn't work. It would be fine if we were hopping on a number line, but my first Graders don't understand that when you are dealing with real objects you can't take away more than you started with. Please add an option to lock negative numbers and I would give it 5 stars.
Review by Reading Buddies on Subtracting Sardines HD.