一 、 口 算
结 果 请 用 最 简 分 数 表 示
21 +31 = 21 -41 = 52 -51 = 74 -71 = 87 -83 = 1 01 + 52 = 65 -32 = 31 +51 = 83 -41 = 32 +31 = 1 25 -1 25 = 1 09 -1 01 = 54 -52 = 61 + 31 = 21 -81 = 83 +83 = 21 -51 = 74 +73 = 1-87 = 65 +65 = 1-1 25 = 53 +21 = 1 09 -1 03 = 75 -75 = 83 +85 = 61 +1 27 = 41 +43 = 73 +21 = 1 09 -21 = 1 09 -53 = 59 + 89 = 18 + 78 = 1924 - 1324 = 1936 + 336 =
37 + 47 = 118 - 18 = 14 - 19 = 1213 - 313 = 89 +411 + 19 = 1- 16 - 16 = 34 + 14 + 14 = 78 - 38 + 38 = += -= += -= += -= 二 、 计 算 ( 能 简 算 的 要 简 算 )
( 1) 58 - 310 + 14 ( 2) 1- 124 + 548 ( 3) 34 + 215 - 112 ( 4) 535 - 223 +316 ( 5) 57 - 415 + 27 - 215 ( 6) 134 -﹙34 -23 (7 )2 -18 -78 ( 8) 123 + 538 - 334 ( 9) 45 - 14 + 13 ( 10) 910 + 320 - 315 ( 11) 1- 712 +34 ( 12) 2728 + ﹙ 1314 - 57 ( 13) 256 -﹙ 23 +712 )( 14) 1514 -