This is a math Activ Studio Flipchart that teaches subtraction concepts, i.e. using symbols to subtract. This lesson aligns with the Houghton Mifflin Math Textbook series. The flipchart begins with the Problem of the Day, in which students are to solve a constructed response subtraction word problem using hands-on manipulatives on the Activ Board. Next, it reviews the subtraction symbol and what a subtraction sentence looks like. Next, the students demonstrate on a calendar with counters to