Virginia Escobar-Cheng teaches a science class at a high school in Homestead, Florida, in March.

Schools throughout the country are grappling with teacher shortage, data show

Updated 1745 GMT (0145 HKT) August 21, 2017

(CNN)Lynn Sorrells started teaching 26 years ago because she loved seeing the light-bulb moment when a kid grasped a new concept.

She still does. But as principal of a high school in Dorchester County, Maryland, she is struggling to find an algebra and geometry teacher just weeks before her school year is set to begin.
As students head back to school, Sorrells' district is one of hundreds across the country grappling with a growing teacher shortage -- especially in key areas such as math and special ed.
"Currently, there are not enough qualified teachers applying for teaching jobs to meet the demand in all locations and fields," said the Learning Policy Institute, a national education think tank, in a research brief in September.
Some schools, such as in New York City, are being forced to increase class sizes, which some studies show can reduce how much a student learns.
The institute estimated last year that if trends continue, there could be a nationwide shortfall of 112,000 teachers by 2018.

What subjects are most affected?

Public schools in 48 states and the District of Columbia report teacher shortages in math for the 2017-18 school year, according to the US Department of Education. Forty-six states report shortages in special education, 43 in science and 41 in foreign languages.
Statistics on shortages may be based on the percentage of unfilled teaching jobs, the number of emergency credentials given to those without traditional teaching certificates and the number of teachers hired after the school year starts, says Dan Goldhaber, director of the University of Washington's Center for Education Data and Research.
It's always been harder to fill teacher jobs in math, science and special education positions, Sorrells said. But the past five years have been worse than usual.
Increasingly, she said, teachers i