First find the total amount Jackson still needs to collect: $1000 - $300 - $40 = $<<1000-300-40=660>>660
Then subtract the number of days he already worked from the number of workdays in the week to find how many more days he'll work: 5 days - 2 days = <<5-2=3>>3 days
Then divide the total amount he still needs to earn by the number of days he has to earn it to find how much he needs to earn per day: $660 / 3 days = $<<660/3=220>>220/day
Then find how much money he collects per house: $10 / 4 houses = $<<10/4=2.50>>2.50/house
Then divide the amount he needs to collect per day by the amount he collects per house to find how many houses he needs to visit per day: $220/day / $2.50/house = <<220/2.5=88>>88 houses/day
#### 88