Interactive spreadsheet

In the excel spreadsheet I wrote multiplication facts that a third grader would know.  I had worked with excel briefly before so I found it to be not as difficult.  It was hard when I had to type the formula in over and over again in each row because I kept leaving out a symbol which messed up the whole formula.  I had never used the privacy or hidden tools which I think will be very useful in the classroom.  The students can't change what is already written but they are able to type and re type their answers.  I can see myself using this in the classroom for 3rd to 5th graders.  They will be able to complete the spreadsheet just like a worksheet but will automatically know if their answer is right.  The automatic feedback will be helpful so they can try again until they receive the right answer.  The only thing I didn't like on excel was their very limited amount of clip art images.  I expected excel to carry simple math images but could hardly find any.