(Portland, OR) -- Classes are canceled again today in the Portland Public Schools district as the teachers' strike enters its seventh day. The strike began last Wednesday following months of failed contract negotiations between the district and the teachers union. Negotiations are expected to continue today. Yesterday, Governor Tina Kotek directed the state's chief financial officer to help both sides get financial numbers they can agree on. The district says the teachers union is calling for changes that would cost 220-million dollars more than it currently has in its budget. Teachers say the district has the money to meet their demands. The Portland Association of Teachers is demanding smaller classroom sizes and a pay raise of 21-percent over three years.