加减法，分清楚。 两边求和用加法，如有变少用减法。,3 + 2 = 5,5 2 = 3,2,1,0,4,0,4,19+0=19 0 +88= 88 100+0=100_ + 0 = _,19-0=19 88-0=88 100-0=100_ 0 = _,19-19= 0 88-88=0 100-100=0_ _ = 0,排排队,1,4,5,3,2,0,练一练,1+0= 0+3= 2+0= 4+0= 5-0= 3-0= 7-0= 8-0=,任何数加0、减0，都得原数。,2-2 = 4-4= 3-3= 5-5= 8-8= 9-9= 7-7= 6-6=,相同数字相减，都得0。,1,2,5,7,3,4,3,8,0,0,0,0,0,0,0,0,
