Estimate using general rule 640+892.
Step 1 : Estimating to nearest hundred
640to600892to900
Step 2 : Adding them
600+900=1500
Hence , estimate sum is 1500
Estimate using general rule 586-313.
Estimate the product using general rule : 5381×3691
Estimate the product using general rule 1493×793
Estimate the product using general rule :8950×36
Estimate the following using the general rule :730+998