Illustration of the superposition of two angles to compare magnitudes of the same kind.

Illustration comparing the fundamental units of measure quart and liter.

1, Epyornis; 2, Ostrich; 3, Cassoway; 4, Wild Goose; 5, hen; 6, Pigeon; 7, Humming-bird; 8, Eagle; 9,…

This chart of comparisons can be used with the following questions: "Which line is twice B? Which two…

Illustration used to compare the volumes of a cone and a cylinder by emptying sand from the cone into…

Illustration used to compare the volumes of a cone, a sphere, and a cylinder.

Illustration comparing the fundamental units of measure 1 cubic yard and 1 cubic meter.

Illustration used to compare the surfaces of a cylinder and a sphere.

Illustration used to compare the volumes of a pyramid and a prism by emptying sand from the pyramid…

Illustration comparing the fundamental units of measure 1 square yard and 1 square meter.

Illustration comparing the fundamental units of measure ounces to grams and pounds to kilograms.