my husband is a tax consultant at a firm in oshawa and have quiet a few clients who have daycare businesses and enter all grocery receipts, then will ask/confirm with client what is the percentage of the groceries are for daycare use.

there is no rule of thumb as per cra how much to claim but generally it is anywhere from $6-$8 per child.

it is best to keep the receipts of course because cra does audit home daycare businesses