Another way to think about it: for every 100 units in 10, you take 26. That adds up to 2.6.
On a 26% off sale, an item originally priced at $10 would be discounted by $2.6, bringing the price to $7.4.
Whether you are calculating a discount, a tax, a tip, or a commission, the math is always the same: multiply 10 by 0.26.