Although the Farm School Math Program, Patterns in Arithmetic, developed before "Common Core" and other current states curriculum mandates, there are lessons that correlate with specific standards. Our math series fulfills some of the Common Core Standards.
Nonstandard breaking up for subtraction, addition, and nonstandard measurement, for example, are lessons in this developmental sequence that are not generally found in other programs.
Patterns in Arithmetic: Addition - Booklet 3 - Regrouping into Four Digits
Common Core Standard
Entire booklet 3 NBT A2