Let’s dive into the world of decimal arithmetic?

To kick things off: what is decimal arithmetic anyway? It’s just a fancy way of saying “adding and subtracting numbers that have decimals.” Yup, you heard me right no more boring old whole numbers for us! We’re going to be working with fractions and decimals all day long.

So let’s say we want to add 0.25 + 0.17. Now, if you’re like most people, your first instinct might be to grab a calculator or pull out some fancy math software. But hold on there, cowboy! We can do this by hand and it’s actually pretty easy once you get the hang of it.

To kick things off: we need to line up our decimal points so they’re in the same spot. In this case, that means moving the 0.17 over two places to the left (since there are two digits before the decimal point). So now we have 0.25 + 0.017.

Next, we need to add those numbers together. Easy peasy! Just write down each digit and carry any extra ones over if necessary:

| 2 | 5 |
| —–|——- |
| 0 | 17 |
| | |
| | |
| | |
|——|——–|
| 0.32 | 0.17 |

Whoa, hold on there! Did you see that? We got a decimal point in the ones place (the rightmost column) but we only wanted two decimal places total. So what do we do now?

Well, if you’re like most people, your first instinct might be to round off that last digit and call it a day. But hold on there, cowboy! We can actually adjust our answer by moving the decimal point over one place (since we only wanted two decimal places total). So instead of 0.3217, we’ll write down 0.32:

| 2 | 5 |
| —–|——- |
| 0 | 17 |
| | |
| | |
|——|——–|
| 0.32 | 0.17 |
| | |
| | |
| | |
|——-|———|
| 0.49| |

We’ve added two decimal numbers together and adjusted our answer to fit within the desired number of decimal places. It may not be rocket science, but hey we’re math nerds here, so that’s a win in my book!