Elixir Ink

This Google Sheets Pixel Art activity image is inserted in the sheet alongside math questions.  Each of the pixels from the images has color that will only appear a correct answer being typed into a particular cell.  Once students answer a question correctly, those colored cells of the picture appears.  As students complete the questions, the previously hidden image reveals itself.  This also gives students a quick self-check. If students try to type an incorrect answer, no color will appear on