Huawei Honor 3C H30-U10 Quick Start - Manual (Page 11)

Turning on one-hand UI
In one-hand UI mode, dialing numbers, texting, and other
routine activities are easy to accomplish with one hand.
Go to and touch One-hand UI to turn on one-hand UI.
You can touch the arrow on either side of the screen to move
the dialer or other operation area to the side of your choice.
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