'by subtracting from' is correct and usable in written English.
You can use it when you want to describe the action of removing an amount from a total. For example, "We calculated the final cost by subtracting from the original amount."
Net investment income (NII) is calculated by subtracting from income expenses properly allocable to that income.
The ambitions of many of its most talented members can be satisfied not by adding to the total output but simply by subtracting from someone else's.
The union has honored their objections by subtracting from their special payments the same 44% that it subtracts from each of their ordinary monthly payments.
The area per grid cell, in square kilometers, is calculated by subtracting from the area of the grid cell those portions that are permenantly inundated.
It may be that the fear of global warming is now so, well, global that people are trying to do their bit by subtracting from the earth's garbage load.
The script – now by adding to the original story, now by subtracting from it – took its own weird course, but somehow the arc survived and so did the passion.
The area per grid cell (Areakm) is calculated by subtracting from the area of the grid cell those areas that are permanently inundated as identified using VMAP (0)/Digital Chart of the World.
The area per grid cell (item Areakm), in square kilometers, is calculated by subtracting from the area of the grid cell those areas identified as being permanently inundated using VMAP 0).
Gross receipts under this provision are computed, however, by subtracting from actual gross receipts collected during the payment period the amount by which $80,000 exceeds such actual gross receipts.
The cash flow was derived by subtracting from newspaper earnings $6 million for depreciation and $22.9 million for pension contributions the company does not need to make because its pension plan is over-funded.
Modern economists have raised similar concerns about today's redistributive welfare states: by subtracting from the rewards of work and adding to the consolations of idleness, social transfers sap economies of their vigour.
