Lots of people would be happy to try to help you, but you need to provide some information before people can make suggestions.
Where did the family live at the various census dates? If these were childhood deaths, those are the places to look for records and/or burials. Do you know where any of them (grandparents, and/or any of their other children) are buried? (It's not unusual for a parent to arrange to be buried where a child was buried, especially if the child died young.) Do you know where any of the family members (grandparents, or their children) were married? Any information available about family members' occupations, etc.?
The more specific information you can give us about what you already know, the more likely that someone can point you in the right direction - that's especially true if one or more of the children may still be alive (that is, didn't die, but just lost touch with the family), which makes it more tricky.