Math Lecturer Explains How Solving Addition & Subtraction Problems From Left To Right Is Far Simpler

Apr 25, 2023

When asked which subject they found the most difficult or stressful to learn in school, many would be remiss if they didn’t put math up there. While some are naturally gifted with the ability to figure numbers out, for many of us, it took a lot of hard work and nights burning the midnight oil to commit formulas to memory. It turns out, however, that there may be different, quicker and far easier ways of solving simple addition and subtraction problems that you may have been taught when you were younger.

Fresno State mathematics lecturer Howard Hua has now taken the internet by storm and blown minds by simply offering alternative methods to getting to the bottom of basic math problems. It’s likely you were taught to solve these numerical problems by moving through the numbers from right to left. Hua, however, has shown the efficacy and efficiency of solving such problems by taking a different approach – from left to right.

In a clip of Hua’s left-to-right method of solving multidigit addition problems, he showed viewers how to add triple-digit numbers by sectioning off the larger, middle and single-digit numbers before putting them all back together in a matter of seconds. “Now, I know a lot of us were taught to add right to left, so that’s considered the default, but I think given context, a lot of us would naturally add left to right,” he explained. 

Viewers lauded Hua’s method, with many commenting that they might have performed better in school had they known this technique. Luckily for us, solving math problems from left to right also works for basic subtraction problems as well.

In another clip explaining the left-to-right subtraction method, Hua began by showing how to solve a double-digit problem. Instead of the usual “borrowing” and “carrying over” method intrinsic to the right-to-left method, Hua’s explanation required no such things. Instead, he subtracts as usual unless the lower number is larger. Here, he then employs a minus. In his example of 82 - 35, he started by subtracting the left number first – that is, 8 - 3 = 5. When subtracting 5 from 2, he ends up with -3. Taking the 5 to mean 50, he subtracts 3 from it to get the answer, 47. 

Hua also illustrated how the method can be utilized for triple-digit numbers, as well as another way to subtract numbers that include a lot of zeros. “If you ever have a number that has a lot of zeros at the end, just subtract one from both numbers, which might make the problem easier for you. … Why does this work? This strategy is called ‘same distance, same difference.’ We can think of subtraction as, ‘what’s the distance between these two numbers on the number line?’ So if we lower both numbers by 1, it’s the same distance, meaning we get the same difference,” Hua explained. 

Viewers were again enthralled by his approach.

“Supercool. If all methods were taught, different learners could catch on with what their brain likes the best,” one enthusiastic viewer wrote, while another said, “personally i feel like not only is this easier, it teaches you what you’re actually doing with the numbers rather than just going thru the motions.”

While more complicated math may forever remain just outside the bounds of many of our abilities, at least we’re now equipped with some seriously easy methods to solve some basic addition and subtraction problems.

What do you think of Hua’s methods? Does the left-to-right method make it easier for you to solve basic math problems? Let us know and be sure to pass this on to friends and family so they can learn the mindblowing approaches, too.