Number of the Day in the computer lab

It was Day 5 on the school calendar today, and (usually) on Day 5, I bring the class into the computer lab to work on their Number of the Day exercises. Many of the exercises are similar to what they do most other days in their Number of the Day books. However, I really enjoying bringing them into the lab to do this, because (with a little help from Mr. Rod Epp, one of our division's K-12 Technology Integration consultants, and Mrs. Kroeker's husband, Clinton), I've designed a tool where the students receive feedback on whether their work is correct or not. The tool (created in MS Excel) does not tell the students the right answer - only whether they are correct or not (via a 'thumbs-up' or a 'thumbs-down'). Also, for creating their number sentences, it will tell them 'TRUE' if the sentence is correct or 'FALSE' if it is incorrect. The beauty of this is that it forces the student to go back and double-check their work, and see where they need to 'fix it up'. While the classs was working on their increasing and decreasing number patterns, one student had decided that he wanted to create a decreasing number pattern of -20, starting at 91 (today's Number of the Day). He was quite confident that he had everything correct up until the last number (as he had double-checked everything else), when he went into negative numbers (which we really haven't worked on much to this point). He had everything that you see in the first picture, except that the last number in his pattern was -11. As a result, there was a 'thumbs-down' beside the pattern. So, on the white board in the lab, we worked on a number line. When I asked him if he was starting at 11, how many would it take him to get to zero, he quickly and correctly answered '11'. When I asked him how many were left to take away, if he had to take away 20, and had already taken away 11, he quickly and correctly answered '9'. I then asked him that, if we started at 0 and took away 9, what number would we arrive at. After a little bit of thought, he smiled and said '-9'. I told him that if he was confident that was the correct number, that he should put it in the last box for his decreasing pattern. Of course, when he did so, he received the 'thumbs-up' from the computer. I love the self-checking that goes on when we do that, and I love how this is creeping into their work when they do their Number of the Day in class with paper and pencil. It's helping my students to realize, on a more frequent basis, that it's not just whether you have an answer that counts... it's whether it's a correct one!