A typical conversation between migrant worker Fan Tongsheng in Beijing and his 9-year-old son in the Guangxi Zhuang autonomous region goes as follows.
"How's your schoolwork?"
"How's your health?"
"Everything all right at home?"
"All is good."
The dialogue between the two is a clear reflection of the increasing distance Fan said he feels from his son, who lives with his grandparents in a small village.
His wife also spends very little time with their son, working in a nearby city since the boy entered kindergarten.
Their child is one of many youngsters in a group that is growing in numbers by the day - known as "left-behind children". One or both parents of such youngsters typically work far from home and leave them in the care of grandparents or relatives.
A report released by the All-China Women's Federation yesterday estimated there are about 58 million such children aged up to 17, compared with 22 million in 2004.
"With the rapid increase in the number of migrant workers, the number of left-behind children is also rising fast," Jiang Yongping, director of the federation's women's research institute, said.
"About one in four of all children living in the countryside has been left behind," Jiang said.
Experts have expressed concern that the educational level of adults taking care of these children are generally low and can often only take care of children's basic needs and not their educational and emotional ones.
About 40 million left-behind children are under 14. They are often left on their own, statistics have shown.
"The younger the child, the greater and more important his or her need for emotional support - the most important being from the child's own parents," Professor Zheng Xinrong from Beijing Normal University said.
Zheng called for the government to invest more in building kindergartens and care centers in rural areas for the children.
Wang Dai, director of the basic education department of the Ministry of Education, said various agencies, including the ministries of education, civil affairs, and labor and social security, should provide better management of left-behind children.
"Government departments should work together with nongovernmental organizations to mobilize more social support and safeguard the healthy development of left-behind children," Wang said.