Addition and subtraction can be sloved by using two strategies:ncounting on/back. rounding and compensating.
Counting on is adding forward using fingers, when the number added is under ten. Counting back is subtracting using fingers, when the number subtracted is under ten.
Addition and subtractionRounding and compensating is rounding the added or subtracted number to nearrest tidy number, then compensating for the rounding. Compensating is done by spliting the new number in the old number and the leftover.
Counting on/back and rounding and compensating are easy stategies to use for addition and subtraction, when numbers get too big to solved with basic facts.