ETC pioneered the use and combination of black and white photography with full color pictures to point out individual parts of a whole. Similar to our elementary "parts of..."...
The exercises of the Short Bead Chains prepare the child for multiplication as he ‘skip-counts’ the bead chains. Also included is a bead square for each number 1-10.
This set of material represents three cases of the Theorem Of Pythagoras. In the first, 2 sides of the triangle are equal; in the second, the sides of the triangle are in the...