Illustrate the properties of addition (commutative and associative, identity) and apply each in appropriate and relevant situations
Visualize, represent, and add two-digit by three-digit numbers with sums up to 1000 without regrouping;
Visualize, represent, and add three-digit by three-digit numbers with sums up to 1000 without regrouping
Visualize, represent, and add two- and three-digit numbers by three-digit numbers with sums up to 1000 with regrouping