手脑速算教程及练习(13)

38+58-29-18+12=                          88+10-29-37+19=

99-77+33-51+24=                          59+12+23-91+69=

64+18-44-19-17=                           78+21-39-38+18=

60-23+45-18+22=                          86-12-18+35-38=

57+24-63+31+16=                          17+37-36+50+23=

61-24+46-19+23=                           87-13-19+37-39=

56+23-69+32+15=                           19+35-34+52+25=

63-26+48-17+26=                           85-17-19+35-37=

55+24-71+38+19=                           21+37-36+54+27=

65-28+16-15+27=                            83-17-19+38-33=

26+44+35-54-43=                            38+8+27-38-5=

21+31-28-15+79=                            59+29-46+21-6=

46+38-66+17+5=                             86+10-29-35+19=

56+27-24+17-43=                            57-36+27-21+26=

37+57-29-15+12=                            78+10-29-35+19=

99-77+43-52+24=                            69+12+13-91+69=