Further we suggest to pass to the review of firms - manufacturers and concrete models of electronic books and on the basis of the received information to make the choice. (e-ink-reader.ru)
Add subtract multiply and divide decimals to hundredths using concrete models or drawings and strategies based on place value properties of operations and / or the relationship between addition subtraction; relate the strategy to a written method and explain the reasoning used. (nationalmathfoundation.org)
Algebra tiles provide concrete models for concepts that students may find difficult to (goalbookapp.com)