Lab46 Wiki

This program will focus on a simple mental math trick: calculating the square of a multiple of 5.

This trick works with any multiple of 5 up to three digits (5 to 995), and can be done without much difficult math or a calculator.

Let's take an example number: 105. To calculate the square of 105, we can split the number into two parts, then perform a set of calculations on each part, in order to get our answer.

The two parts we want to split our number into are as follows:

• The “back” part of the number, which is the 5 at the end of the number (this will be the case for every number).
• The “front” part of the number, which is the digits before the 5. (In this case, it is 10).

Calculating the back portion is easy, we just need to multiply 5 by itself to get its square:

5 * 5 = 25

To calculate the front portion, we take our number (10), add one to it, and multiply these two values together to get the front portion of the answer:

10 * (10 + 1) = ?
10 * 11 = ?
10 * 11 = 110

Finally, we bring the two portions back together to get our answer:

110 25
11025
105 * 105 = 11025

In the project files that you grabbed, there is a reference program, “ref.sof0.x86_64”, that you can run to verify your program.

This reference program will run a version of sof0 similar to what you will be creating, where you can enter a multiple of 5, and it will output its square.

You can use this reference to check the output of the program you will be writing, along with the format of the output.