AngularJS表达式{{value + value}}在IE或Edge中不起作用

Question

我的输入字段包含以下表格：

<td class="col-sm-4" ng-bind="getOrderNameForHourRegistration(selectedProject)"></td>
<td class="col-sm-1">
    <input ng-model="addMonday" class="col-sm-1 form-control" type="number" min="0" max="8" value="" ng-maxlength="1" />
</td>
<td class="col-sm-1">
    <input ng-model="addTuesday" class="col-sm-1 form-control" type="number" min="0" max="8" value="" ng-maxlength="1" />
</td>
<td class="col-sm-1">
    <input ng-model="addWednesday" class="col-sm-1 form-control" type="number" min="0" max="8" value="" ng-maxlength="1" />
</td>
<td class="col-sm-1">
    <input ng-model="addThursday" class="col-sm-1 form-control" type="number" min="0" max="8" value="" ng-maxlength="1" />
</td>
<td class="col-sm-1">
    <input ng-model="addFriday" class="col-sm-1 form-control" type="number" min="0" max="8" value="" ng-maxlength="1" />
</td>
<td class="col-sm-1">
    <input ng-model="addSaturday" class="col-sm-1 form-control" type="number" min="0" max="8" value="" ng-maxlength="1" />
</td>
<td class="col-sm-1">
    <input ng-model="addSunday" class="col-sm-1 form-control" type="number" min="0" max="8" value="" ng-maxlength="1" />
</td>
<td class="col-sm-1">
    <input class="col-sm-1 form-control" disabled type="number" value="{{addMonday + addTuesday + addWednesday + addThursday + addFriday + addSaturday + addSunday}}" />
</td>

这：

value="{{addMonday + addTuesday + addWednesday + addThursday + addFriday + addSaturday + addSunday}}" /></td>  

在chrome和firefox上完美运行。但我不能让它在IE和Edge上工作。 它只是没有显示值甚至不为零。根本没有价值......