Decomposing
640-430=
210
134-128=
6
433-122=
311
Do you need to regroup?
453-261
Yes, the tens place. You only have 5 tens and need to subtract 6. Regroup a one hundred into a ten.
770-56=
714
112
467-58=
409
Decompose
478
400+70+8
532-141=
191
619-461=
158
212-190=
22
Which needs regrouping?
435-246
Tens Hundreds both
Both
946-489=
457
888-295=
593
512-379=
133
Does this need regrouping?
746-572=
Yes, the hundreds place needs to be regrouped so a hundred regroups into a ten.
877-697=
180
912-672=
240
524-157=
367
Solve this by counting on
684-348=?
336