It was about 12 years ago when Paul Britt noticed a problem. His students were struggling with subtraction, using algorithms they learned from addition that did not translate to the new operation ...

Subtraction is when you find the difference between two values. Find out how to subtract, or take away, with this KS2 Bitesize maths guide.

So the way to subtract 38 from 325 involves establishing the difference between 38 and 40 (2), 40 and 100 (60), 100 and 300 (200), and 300 and 325 (25).

Ellis showed a subtraction problem, performed both using the traditional regrouping, or borrow-and-carry, algorithm and using an example from the common core. Here’s a screenshot of the two methods.

Former teacher shares subtraction strategy in math book for children , Just after David Costa was nominated for the "Disney Teacher of the Year" award at the Gidley School in Dartmouth, he decided … ...