Math, Economics, Data of all kinds: ECON

https://data.census.gov/cedsci/

The NGHIS  offers data through a variety of sources including IPUMS and more. What ARE these sources? National and International data from the Census and more, allowing researchers to dig deeply into topics such as health, historical, and educational statistics.  ECON, Health, Agriculture, Math and other science student researchers can use the data found here. 

Check out:

NOTE:  these data sets are often complicated for students. Consider scaffolding information from these sites for specific lessons:

FRED: current data

ALFRED: archival data

FRASER: primary documents on economic history from the late1800's.