It can't be typed with the input method that comes with iPhone. You can download an input method software in the App Store. Then select √ and × in the column with software disk or special characters in the settings, or directly enter a check mark and a cross.

Setting steps of custom symbols in mobile phone sogou input method:

1. Find the sogou input method icon on the desktop, and then open the sogou input method interface.

2. Click on the three points in the upper right corner of sogou input method, and then select Settings in the selection.

3. Click Enter Settings in the Settings interface. In Input Settings, select Custom Symbol Settings.

4. At this point, you start to set the custom symbol, select the corresponding status, and then click the corresponding symbol.