The Metric Marvels is a 1978-1979 series of seven animated educational shorts featuring songs about meters, liters, Celsius, and grams, designed to teach American children how to use the metric system. They were produced by Newall & Yohe, the same advertising agency which produced ABC's Schoolhouse Rock! series, and first aired on the NBC television network in September 1978. The spots were shown three times each Saturday during the children's programming block for the 1978-79 season.
On December 23, 1975, President Gerald Ford signed the Metric Conversion Act into law; this act gave official sanction for the United States to convert to the metric system of measurement. At the time the United States mainly used the U.S. Customary system. Ford's presidential successor, Jimmy Carter, began to implement this law in earnest, helping to set up the U.S. Metric Board as a task force to determine when and how the U.S. would convert to metric. The USMB suggested that the transition ought to be voluntary and gradual, taking place over at least a ten-year period.
As part of this gradual transition, the USMB sponsored a number of public service announcements on radio and television. The Metric Marvels was one such television PSA, aired during NBC's Saturday morning cartoons. The shorts featured four animated metric superheroes: Meter Man, Liter Leader, Super Celsius and Wonder Gram. Each superhero performed songs designed to teach children the difference between the old English system and the new metric system.
- "Meet Meter Man" / Superhero Meter Man helps people convert length and distance to metric terms
- "Mara-Mara-Marathon" / The difference between miles and kilometers
- "I'm Your Liter Leader" / Superhero Liter Leader explains the difference between gallons and liters
- "Eeny, Meeny, Miney Milliliters" / Liter Leader uses recipes to explain milliliters
- "Super Celsius" / Superhero Super Celsius explains the Celsius temperature scale
- "Wonder Gram" / Superhero Wonder Gram expresses her weight in grams
- "Wonder Baby" / A young Wonder Gram converts pounds to kilograms
The series shared the animation style, song quality and voice actors of the popular Schoolhouse Rock! on rival network ABC. Incoming NBC president Fred Silverman, formerly of ABC, may have thought to replicate the success of that show; he had also brought over another short-form cartoon series, Time for Timer, from ABC in 1978. Despite this, the series was pulled from the air after a single seven-episode season. Being separated from Schoolhouse Rock! prevented the series from having an afterlife in reruns. Moreover, at the time NBC was ranked third place in viewership among the three dominant television networks.
Ultimately, Americans did not fully "go metric". Governments did not require the metric system for public works within their jurisdictions, such as use on road signs, which might have encouraged adoption. The United States Metric Board was dissolved in 1982, and metrication was not a public policy priority until the 1991 Executive Order 12770.
The Metric Marvels was released on VHS for educational buyers only in 1979 by Newell and Yohe, Inc.; Center for Humanities Mount Kisco, NY. This release was in color and included one videocassette (approximately 17 min., 30 sec.) and seven teacher's guides, described as "seven 2 1/2 minute segments in which four animated superheroes explain the metric system" and carried the note "Previously issued as seven filmstrips by Xerox Films". The Xerox Films filmstrip release was described as "Elementary and junior high school, Filmstrip" and included seven 35 mm color filmstrips (approximately 200 fr.), seven audiocassettes and five teacher's guides.  Xerox Films was a producer of films for schools and libraries, and was one of the 10 companies making up The Xerox Education Group at the time. 
- Erickson, Hal (2005). Television Cartoon Shows: An Illustrated Encyclopedia, 1949 Through 2003 (2nd ed.). McFarland & Co. p. 540. ISBN 978-1476665993.
- Woolery, George W. (1983). Children's Television: The First Thirty-Five Years, 1946-1981, Part 1: Animated Cartoon Series. Scarecrow Press. pp. 180–181. ISBN 0-8108-1557-5. Retrieved 14 March 2020.
- Perlmutter, David (2018). The Encyclopedia of American Animated Television Shows. Rowman & Littlefield. p. 387. ISBN 978-1538103739.
- Worldcat: See External Links
- New York Times: "Xerox No Dropout" By William D. Smith, December 27, 1970, Page 103