1.3.1 有理数的加法（2）,课前练习,1、口答：,异号两数相加，取_ _ _的加数的符号， 并用较大的绝对值_较小的绝对值.,一个数同零相加_.,仍得这个数,相同,相加,绝对值较大,减去,同号两数相加，取_的符号，并把绝对值_；,互为相反数的两数相加得_ .,零,试一试,267,276,3626,146,185,19,33,10,20,13,你能说出下列各式的得数吗,1.(+4 )+(+7 ) (-4 )+(-9 ) (-11)+(-6 ) (-4 )+(-7 ) (+9 )+(+4 ) (+9 )+(+14),2. (+5) +(-2) (-5) +(+2) (-4) +(+9) (+4) +(+9) (-13)+(+6) (+13)+(-6),?,=+ 11,= -13,= -17,= -11,=+13,=+23,= +3,= -3,=+5,=+13,= -7,=+7,例1 计算：,(1) (-11) + (-9); (2) (-3.5) + (+7); ( +9) + (-10.2); (+2.7 ) + (+3.5); (-1.08) + 0; (+3.2) + (-3.2
