Make a ballpark estimate .Use the column-addition method to add.
compare your answer with your estimate to see if your answer make sense.
89
+47
=
ballpark estimate:
634
+86
=
ballpark estimate:
148
+77
=
ballpark estimate:
481
+239
=
ballpark estimate:
746
+827
=
ballpark estimate:
508
+1,848
=
ballpark estimate