Tools

Hands-on tools to play with, open to everyone. Sign in to save your work where a tool has a File menu.

• Balance Scale

  Drag weights onto the pans and watch the scale swing.

• Steelyard

  Slide the poises along the arm to weigh a mystery object.

• Compass and Straightedge

  Draw lines and circles; every crossing is a point to build on.

• Dissection Puzzles

  Move, turn and flip pieces to build a shape, including picture proofs of Pythagoras.

• Area Diagram

  Multiply part by part and see the areas add up to the product.

• Area Observer

  Measure to the right and down from the origin, and see the area on graph paper.

• Abacus

  A base-ten abacus: press a bead to count it.

• Trebuchet

  Set up a counterweight trebuchet and launch stones at the tower.

• Proofs

  Proof diagrams that move step by step.

• Function Plotter

  Type a rule like y = 2x + 3, see its graph, and make a table of points.

• Calculator

  A scientific calculator that shows fractions, roots and powers the way they are written.

• Unit Circle

  Drag the point around the circle and read the angle, sine, cosine and tangent.

• Zoom Demo (experimental)

  Try the page zoom: pinch off the scale, or use the − + Fit buttons.