Obviously, the higher the rate of interest, the faster your savings will grow. Figure 1.4 shows that a few percentage points added to the ( compound ) interest rate can dramatically affect the future balance of your savings account. For example, after 10 years $1,000 invested at 10 percent will grow to $1,000 x (1.1)^10 = $2,594 . If invested at 5% , it will grow to only $1,000 x (1.05)^10 = $1.629.