A rule can be used to quickly divide a board into equal parts. Lay the rule on the board with the start of the scale against one edge. Then angle the opposite end to a number that is easily divided by the number of parts you want. (If you want to divide a board into three equal parts you might use 9 and mark the board at 3 and 6.) Likewise, if you need four equal parts, angle the rule to numbers divisible by four, like 8, 12 or 16.
The monthly mortgage payment mainly pays off principal and interest. But most lenders also include local real estate taxes, homeowner’s insurance, and mortgage insurance (if applicable).