The document provides instructions to find the sum and difference of several numbers. It tells the reader to estimate the sums and differences to check if the answers are reasonable, and also to check differences by doing the inverse operation of addition. The document then lists several numbers for the reader to practice finding the sum and difference.

1. Find the sum. Estimate to check if it is reasonable.<br /> 469 312<br /> 308 477<br /> 529 210<br />+ 637 + 390<br />Find the difference. Check with inverse operation.<br />5326 8004 19211 134622<br />-1417 -5361 -8955 -129655<br />