Many children do not receive resuscitation because people are scared to attempt just in case they cause harm. It is always better to try than to do nothing. If the child is unresponsive and not breathing it is much better to perform adult style resuscitation than do nothing.
Although first aiders can perform adult style resuscitation on a child the following minor modifications will make it more suitable:
Give 5 initial rescue breaths before starting chest compressions then continue at 30:2
If you are on your own give CPR for one minute before going for help.
Compress the chest by at least one third of its depth (4cm for a baby and 5cm for a child)
For a baby use two fingers
For a child use one or two hands depending on it’s age/size