ClipArt ETC
"From Figure 4 he sees a parallelogram equal to a rectangle of the same base and altitude. Cut out and paste in rectangle form." -Foster, 1921

Area of Parallelogram

"From Figure 4 he sees a parallelogram equal to a rectangle of the same base and altitude. Cut out and…

"The student sees the trapezoid is equal in area to a rectangle whose base is the average base of the trapezoid, and whose altitude is the same as that of the trapezoid." -Foster, 1921

Area of Trapezoid

"The student sees the trapezoid is equal in area to a rectangle whose base is the average base of the…

"The student sees the trapezoid is equal in area to a rectangle whose base is the average base of the trapezoid, and whose altitude is the same as that of the trapezoid." -Foster, 1921

Area of Trapezoid

"The student sees the trapezoid is equal in area to a rectangle whose base is the average base of the…

A cube after additions have been made.

Cube

A cube after additions have been made.

A visual representation of cubing. "In the diagrams, Figure 1 represents 40 cubed and has a content of 64,000 cubic units; Figure 2 represents 3(40 squared x 8) and the contents of these three blocks are 38,400 cubic units; Figure 3 represents 3(40 x 8 squared) and the contents of these blocks are 7,680 cubic units; Figure 4 represents 8 cubed or 512 cubic units." -Foster, 1921

Cubing

A visual representation of cubing. "In the diagrams, Figure 1 represents 40 cubed and has a content…

The shaded region represents 5/8 of the rectangle. If II is divided in to thirds, then those pieces are equal to the five in I.

Five Eighths

The shaded region represents 5/8 of the rectangle. If II is divided in to thirds, then those pieces…

The shaded region represents 3/7 of the rectangle. I and II are the size of 3 IIIs.

Three Sevenths

The shaded region represents 3/7 of the rectangle. I and II are the size of 3 IIIs.

The shaded region represents 2/5 of rectangle. III can be compared to I and II to find that it is made I is made up of 2 IIIs.

Two Fifths

The shaded region represents 2/5 of rectangle. III can be compared to I and II to find that it is made…

The shaded region represents 2/3 of rectangle.

Two Thirds

The shaded region represents 2/3 of rectangle.