More than 2,000 parents in the US, Spain, France, Germany, Romania, Brazil, Portugal, Italy and Russia surveyed. Most parents buy an Android device for their kids when they are 10 to 13 years old. An increasing number of American children aged 7 to 9 and almost 3 per cent of 5 year-olds own one, too. A mobile phone at young ages can expose children to cyber-bullying, sexual predators, malware and fraud. Bitdefender recommends using parental control either as a standalone application or as software.”]
Source: https://www.bitdefender.com/blog/hotforsecurity/children-use-android-as-young-as-5-study-shows/