Each group needs:

• graph paper
• ruler
• pencils
• Ultrasound Imaging Worksheet

To share with the entire class:

• small cardboard box
• box cutter (for use by the teacher)
• LEGO MINDSTORMS EV3 robot, such as EV3 Core Set (5003400) at https://education.lego.com/en-us/products/lego-mindstorms-education-ev3-core-set/5003400#lego-mindstorms-education-ev3
• LEGO MINDSTORMS Education EV3 Software 1.2.1, free online, you have to register a LEGO account first. At https://www.lego.com/en-us/mindstorms/downloads/download-software
• computer, loaded with EV3 1.2.1 software
• LEGO ultrasonic sensor (included in LEGO core set, above); at https://shop.lego.com/en-US/EV3-Ultrasonic-Sensor-45504
• LEGO parts to build a sensor mount; one method: attach sensor using four long LEGO pins and make a cursor/pointer from 1 long LEGO pin, which are items included in the base set (see Figure 1)
• USB cable (included in LEGO base set)
• ruler and marker, to measure and draw a grid on the top of the box corridor (see Figure 1a); to avoid any confusion, number the grid as shown in the photograph; also, choose two grid sizes, such as ½ inch and 1 or 2 inches.
• an assortment of objects from which one (or more) will be hidden in the box, choose objects with simple yet distinguishable shapes, such as a ball, cube, soda can, coffee cup or bowl, that are not too small and that fit in the box

Alternative: LEGO MINDSTORMS NXT Set:

Note: This activity can also be conducted with the older (and no longer sold) LEGO MINDSTORMS NXT set instead of EV3; see below for those supplies:

• LEGO MINDSTORMS NXT robot, such as the LEGO MINDSTORMS NXT Base Set and NXT 2.1 software
• computer loaded with the NXT 2.1 software