(1) 60-7= 5 74= 45-5= 9 45= 37-8=
(2) 26 30= 52 9= 93-60= 26-4= 68-60=
(3) 74-8= 27+20= 59-8= 26-20= 31-6=
(4) 54-30= 7 55= 70-5= 35+5= 82 9=
(5) 40-8= 58+30= 27+7= 95-70= 45 3=
(6) 45 7 = 4 25= 8 25= 52-30= 45-7=
(7) 27 6= 27 8= 20 25= 80+10= 50 7=
(8) 45-7= 68-4 = 64-8= 8 48 = 87-7=
(9) 30+30= 77-7= 39-10 = 39 5 = 45 5=
(10) 83-5= 32 50= 26 40= 14 6= 26 9=
(11) 57-30= 93-9= 50-3= 75-7= 72-5=
(12) 67-30= 30 26= 94-30= 35 20= 19 10=
(13) 85-40= 84 5= 34 40= 58 6= 50-4=
(14) 61-4= 69-30= 72-8= 12-3= 50-6=
(15) 58 10= 64 7= 71-9= 70 8= 34-20=
(16) 14-9 6= 15-8-5= 9 8-9= 14-7 4= 16-7 5=
(17) 50-40+6= 72+8-30= 45+9-30= 34-20+40=
(18) 15–(5 4)= 8 (5 7)= 13–(5 4)= 65-7-40=
(19) 87-9-10= 43-(3 27) = 76-6-8= 39–(9-5)=
(20) 36 40 2= 59-9-20= 63-30 5= 30 (11-7)=
(21) 47 (5 7)= 83-(27-20)= 17 6 8= 43-8-30=