Adding without regrouping
524+223=
747
323+518=
841
749-448=
301
348-139=
209
832+123=
955
505+109=
614
969-839=
130
720-312=
408
449+430=
879
497+256=
753
894-621=
273
239-192=
47
457+432=
889
996+978=
1974
978-766=
212
851-408=
443
655+334=
989
596+928=
1524
979-166=
813
550-290=
260