a=1000-148×3:2+68×8-164
a=1000-444:2+544-164
a=1000-222+544-164
a=778+544-164
a=1322-164
a=1158
b=[(271-169):2+(280+120):4]×2
b=(102:2+400:4)×2
b=(51+100)×2
b=151×2
b=302
c=(820-148×3 :2 ):2-139
c=(820-444 :2 ):2-139
c=(820-222 ):2-139
c=598:2-139
c=299-139
c=160
