Toronto police said the robberies took place in the Crescent Town community at Victoria Park Avenue and Danforth Avenue, and near Eglinton Avenue East and Birchmount Road.
"They removed or ripped gold necklaces from the victims' necks, including one from a five-year-old," police said in a statement.
"In one case, a knife was used to threaten the victim into complying with the demands."
Police say an 18-year-old Toronto man of no fixed address faces multiple charges, including two counts of robbery, assault with a weapon and possession of cocaine.
A 17-year-old from Aurora faces five counts of robbery, threatening death, and assault with a weapon.
Both were scheduled to appear in court at Old City Hall on Thursday.