Tectonic plates are pieces of the lithosphere: crust plus rigid uppermost mantle. They move over hotter, weaker upper mantle that is mostly solid and can deform very slowly. They do not float on a worldwide ocean of liquid magma. Plate speeds vary; a few centimetres per year is a useful scale, not a speed for every plate. Safety: Large paper pieces only. Model does not predict earthquakes or volcanic hazards. Stop: Stop after the three paper motions. No heating, rock compression, soil excavation, or liquid-mantle experiment.

Materials: Paper; Pencil; Ruler; Two large torn paper rectangles 1. Draw a side view with a thin upper band labelled Crust, a thicker band below labelled Rigid uppermost mantle, and a lower region labelled Hotter, weaker, mostly solid mantle. Bracket the upper two bands together as Lithosphere. Split the bracketed region into two plate pieces. 2. Use the two paper rectangles to show three different motions on a flat table: apart, toward each other, and sideways past each other. Draw each pair of arrows. Label them divergent, convergent, and transform. Do not pile or force objects together. 3. Make an illustrative motion strip: mark a start and points 2,4,6 cm away for years 1,2,3 at a fictional steady rate of 2 cm per year. Write that the motion strip shows distance at household scale, not a scaled map of plate thickness. 4. Explain the model in three sentences: what a plate includes; what the underlying material is like; and how the slow-motion record differs from the quick hand movements. Add that plate boundaries are not all the same. Done: A labelled layer view, three boundary-motion arrow pairs, a four-position motion strip, and three explanatory sentences are complete. Proof: Keep the diagrams and strip. Note adult help measuring, distinguishing crust from lithosphere, or moving the cards. Stop: Stop after the three paper motions. No heating, rock compression, soil excavation, or liquid-mantle experiment.