Help your students practice estimating lengths with this interactive deck of BOOMâ„¢ cards! Students will answer questions to estimate length using centimeters, meters, inches, and feet. This deck includes 30 cards perfect for practicing standard 2.MD.3. Multiple card types included to provide a variety of practice. BOOMâ„¢ cards are self-checking task cards that provide immediate student feedback. BOOM cards can be used on interactive white boards, desktops, chrome books, laptops, iPads, iPhones, K