"first elementary" is correct and usable in written English.
It is often used in a phrase such as "first elementary steps" to indicate the initial steps in a process. For example: "The first elementary steps to understanding this complex concept are to break it down into manageable parts."
The first elementary school in the Americas was set up in Mexico in 1523 by a Franciscan monk.
She said she was hired 10 years ago as the town's first elementary school foreign-language teacher.
The first elementary step of CO2 electroreduction to COOH* is used as a detailed example case for illustrating the method.
More than a century after finding that first elementary particle, we are on the brink of an even greater scientific revolution.
The first elementary school in the New World was organized in Mexico by the Franciscan Pedro de Gante in 1523 in Texcoco, followed in 1525 by a similar school in San Francisco.
Their observations were experimentally verified by the English scientist Sir Francis Galton, who suggested the first elementary system for classifying fingerprints based on grouping the patterns into arches, loops, and whorls.
Early symptoms often present during discussion circles at a patient's first elementary-school Diversity Day, and grow in intensity with the introduction to activities such as yoga, listening to rap music, and pointing out that "we all come from Africa".
But it's Plaza Towers, the second elementary school, that's got us by the throats.
Elementary students in the village attend the No. 5 School; a second elementary and early childhood center are in Inwood.
Physicists at Purdue University believe they have discovered a fifth elementary force of nature.
Students at a third elementary school, P.S. 150 in TriBeCa, are also to share space in P.S. 3, on Hudson Street.
