Find 'a' to complete the equation!🚫 No Calculator. #maths #education #thinking #solution #algebra#yt

Added: 2026-05-30

[00:00:04]This problem is difficult and worth a lot of points. So, you definitely need to know how to solve it. Let's look at the question. For problems like this, many students get confused at first glance. Even though they know they need to find a, they don't know where to start. Today, we'll teach everyone two tricks so that next time you encounter similar problems, you can solve them easily. The first method is called factoring out the common factor because if we observe carefully we can see that every digit is an a. Right? So after I factor out a, take a look a times the bracket and inside there's only a one left. So next when you factor out a from a plus a, what's left? Isn't there an 11 left? If you don't quite understand just imagine a plus a as 33. If I factor out a 3 from 33, isn't there an 11 left? Or you can imagine it as 44 where each digit is the same. If you factor out a four, what's left is also 11, right?

[00:00:58]It's the same thing. Then for a a plus a, if you factor out a, what should be left is 111. If you don't get it, you can think of it as 333 or 44. It's easier to understand that way, right? If I factor out a 3 from 333, what's left is 111. So it's 3 * 111. That's what it means. All right. Next, what's left here is 11 + 1 in parentheses, which equals 810. So, can we calculate what's inside the parenthesis? What does it equal?

[00:01:30]135. So, a * 135 = 810. So, for this a, isn't it just 810 / 135? After calculating a equ= 6. This is the first method. What's the other method? It's this horizontal equation. I don't see any pattern or clue in the horizontal format. So if that doesn't work, I'll convert it into a vertical format. All right, let's write this in vertical format. It's equivalent to when a + a when I write a in vertical format, we don't need to draw the horizontal line because it already represents a hole.

[00:02:02]And in the vertical format, it definitely represents a hole. Right? And by not drawing this, it makes it easier for us to observe. Next, it's a plus a.

[00:02:11]Then add another a and then add one more a. Come on. Add them all together. And the final result is 810. Right? Okay.

[00:02:18]Moving on. Look 1 2 3 4 5 oh five identical numbers added together and the last digit is zero. So this a could be 2 4 6 or 8 right? All of those are possible aren't they? Notice we can eliminate some options because think about it the highest digit is just one a and the final result is 8. Even if there's a carryover this a can't be two or four because that's too small right?

[00:02:46]It also can't be eight because eight is too big. So by judging this way, you know it can only be what?

[00:02:53]It can only be six. So you can choose either of these two methods or if you can understand and use both, that's even better. With that, we finished this problem. I suggest everyone give it a like and save it after watching and review it a few more times. Otherwise, if you want to use such a useful method again, you might not be able to find