# Mathematical Treasure: Add-A-Count Scale for Teaching Arithmetic

Author(s):
Peggy A. Kidwell (National Museum of American History, Smithsonian Institution)

Add-A-Count Scale, 1950s, Smithsonian negative number 96-4205-4.

From the early years of the Republic, Americans used objects in arithmetic teaching. New objects tended to come to market when school populations increased substantially, as with the founding of common schools in the 1820s and 1830s and the growth of high schools in the 1890s. During the 1950s, the number of children in the United States grew rapidly. Several manufacturers introduced toys intended to communicate elementary ideas. This Add-A-Count scale, made by Child Guidance Toys of New York City, well illustrates this trend.

The red, white, and blue plastic toy is a balance with weights in the form of numbers. The weight of the weight is proportional to the value of the number. Hence a "3" on one arm will balance a "2" and a "1" on the other. There are two weights for each digit from 1 to 5 and one weight for each digit from 6 to 9, making a total of 14 weights. The weights and scale fit in a paper box, which has on it a drawing of a girl playing with the toy. In the 1960s, the toy was sold by instrument dealers such as Edmund Scientific Company of Barrington, New Jersey. It sold for $1.00—by 1968 the price was$1.50.

A wide range of objects associated with arithmetic teaching that are found in the collections of the Smithsonian Institution are described and shown on the website http://americanhistory.si.edu/collections/object-groups/arithmetic-teaching-apparatus. Textbooks and related printed materials are listed in the catalog of the Smithsonian Institution Libraries.

Index of Mathematical Treasures

Index of Mathematical Objects

Peggy A. Kidwell (National Museum of American History, Smithsonian Institution), "Mathematical Treasure: Add-A-Count Scale for Teaching Arithmetic," Convergence (October 2014)