See below for a video on Estimating with Addition.
To watch a video on Multidigit Addition with Place Value Drawings, click here.
To watch a video on Multidigit Subtraction with Place Value Drawings, click here.
To watch a video on Estimating with Subtraction,
To watch a video on Multidigit Subtraction with Place Value Drawings, click here.
To watch a video on Estimating with Subtraction,