GeoGebra Classroom

# Compound Interest: What Happens as n Gets Larger?

Let's investigate the time it takes for an initial investment to double. You can move the LARGE POINT on the yAxis to change the value of the initial investment (principal). Here, we're looking to explore what happens to the time it takes for this initial investment to double when we let the number of times interest is compounded per year (n) get bigger and bigger. Interact with this app below for a few minutes. Then answer the questions that follow.

How long does it take for an initial investment of \$1000 earning 7% annual interest to double for the case where n = 1?

How long does it take for an initial investment of \$2000 earning 7% annual interest to double for the case where n = 1?

How long does it take for an initial investment of \$1000 earning 7% annual interest to double for the case where n = 2?

How long does it take for an initial investment of \$2000 earning 7% annual interest to double for the case where n = 2?

How long does it take for an initial investment of \$1000 earning 7% annual interest to double for the case where n = 4?

How long does it take for an initial investment of \$2000 earning 7% annual interest to double for the case where n = 4?

How long does it take for an initial investment of \$1000 earning 7% annual interest to double for the case where n = 12?

How long does it take for an initial investment of \$1000 earning 7% annual interest to double for the case where n = 24?

How long does it take for an initial investment of \$1000 earning 7% annual interest to double for the case where n = 100?

List 2 observations you've noticed as you've answered these questions: