# Update the Amount

**00:00**
Currently, the amount stays the same for every step of the `for`

loop. So that’s what you will tackle next. Before your `print()`

function calls, add in a new line where you update the `amount`

variable with every `for`

loop step.

**00:15**
So `amount = amount`

—that’s the current value that `amount`

has—multiplied by the `rate`

, but the `rate`

is `0.05`

, for example.

**00:25**
So you need to put this in parentheses and say `(1 + rate)`

because you want to increase the amount. So now it says `amount = amount * (1 + rate)`

.

**00:41**
Then you can adjust the f-string and the function call below to show the `amount`

in the string.

**00:48**
You can also remove the `print()`

call with the `amount`

and the `rate`

to just show `year`

, and then the year number, and then the `amount`

.

**00:56**
And when you run the module now, then you can see that the `amount`

increases with each year exactly like you want it to increase. But as you can see, it’s not rounded to two decimal places just yet.

**01:10**
But for now, it’s good news that your function generally works, but it doesn’t display entirely what you want to display yet.

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reapyton May 3, 2024I don’t understand the way

amountis updated in theinvestfunction provided in this video. Why do we add 1 to rate?I came up with this solution:

And I also understand the solution given for the same exercise in the

Python Basicsbook:Any help would be appreciated. Thank you in advance.