5: 60+225+40 =60+40+225 =100+225 =325 282+41+159 =282+(41+159) =282+200 =482 548+52+468 =600+468 =1068 135+39+65+11 =(135+65)+(39+11) =200+50 =250 13+46+55+54+87 =(13+87)+(46+54)+55 =100+100+55 =155 5+137+45+63+50 =(137+63)+(5+45+50) =200+100 =300 6: 1337 848 1118 7: 略 思考题 1+2+3+4+5…… 100 =(1+99)+(2+98)+(3+97)+…… +100+50 =100×50+50 =5050 |
本页答案点评