上面一个加号下面一个减号是“±”, 表示正或负。输入方法:
方法一、
1、使用搜狗输入法,找到状态栏,然后右击;
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/d043ad4bd11373f07d84b823a90f4bfbfaed04d7?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
2、在状态栏中找到表情&符号,然后符号大全,点击打开;
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/d058ccbf6c81800aa53f5eb2bc3533fa838b47b0?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
3、在搜索框中输入“正负”,然后就可以在结果中找到“±”号。
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/1e30e924b899a901618f8d8a10950a7b0308f5d0?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
方法二:
1、右击搜狗输入法状态栏,找到软键盘——特殊符号;
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/72f082025aafa40f4ba61f61a664034f78f0192d?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
2、单击点开特殊符号,从弹出来的软键盘中找到“±”号,使用时单击即可。
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/63d0f703918fa0ec36d3b5b12b9759ee3d6ddb72?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
提示:正负号在数学中可以用来表示有理数的正负或者对数进行四则运算中的加减运算。正负号在中学物理中不是单一的概念,它有的等同于数学中有理数的正负,有的则用来表示物理量的性质、方向,情况较为复杂。