There is some basic math literacy lacking in this article. For example, the return on paying down a mortgage with a 3% interest rate is 3%. If savings acco

There is some basic math literacy lacking in this article. For example, the return on paying down a mortgage with a 3% interest rate is 3%. If savings accounts are paying 4% interest, you’ll get a 1% better return by keeping your money in a savings account than by making extra payments on your mortgage. No. If the two options are to place $1,200 in a interest account bearing 4% (compounded monthly), versus contributing an extra $100/month to a mortgage at 3%, the amount "earned" is different. Assuming monthly compounding in both cases, in the 4% interest account case, the final balance is $1248.89, representing a net earning of $48.89 based on the compound interest formula. In the second case, one needs to use an amortization schedule and compare the difference in contributing an extra $100/month, versus not doing so. The difference isn't simply a 1% gain though, because one is paying slightly less interest on a shrinking principal over a 30 year period, versus earning 1% on a growing principal over a 30-year period.