Head teacher Jonathan Parker says that there isn't enough cash to pay for substitutes to cover sick staff.
The children being sent home will miss two classes, but none of them are taking vital GCSEs as they are all in the first three year groups.
Edenham High School
Unusual case
Many head teachers say this is just part of a bigger problem with funding in schools, which they reckon don't get enough money.
But the Department of Education says that Edenham, which owes £90,000, is a very unusual case, and blames Croydon Council for making bad decisions and holding back money.
Mr Parker says he may have to send children home early every month, depending on staff sickness.
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