Estimate $99+61$99+61.
Round both numbers to the nearest $10$10.
$\editable{}+\editable{}$+
Calculate the estimate.
Estimate $63-22$63−22.
Estimate $898-132$898−132.
Estimate $765+171$765+171.
Make estimates of numbers, quantities and lengths and round off answers to reasonable accuracy in the context of a given problem.