Have you ever been like, "Oh I wish there was a trick to multiplying nines?" Well, as it turns out, there is! Nines are very easy to multiply and it doesn't take much to learn the trick. Today, we are going to be learning about multiplying nines.
ISAIAH LOPEZ
Okay so the first multiple of nine is nine. Obviously. The multiple after nine is 18. So to figure that out, you need to ask yourself if all the digits in that number add up to nine. Like in 18, 1 + 8 = 9. Do you get it? Let me put it like this. The number 18 is made up of a 1 and an 8. Together, they add up to 9. After 18 comes 27. 2 + 7 = 9 so that is right. After that, comes 36. 3 + 6 = 9. Now, I hope you have learned. It will get a little tricky after this though.
Some of you might be asking, well how do you get numbers like 99. Well, the answer to that is, you know 9 + 9 = 18. Then do 1 + 8 = 9. Do you see it now. If the sum turns out to be a two digit number, then add those two digits. Still, even with a three digit number, keep repeating until you get to a single number. If that single number you got is a nine, then you know you have it right and that number is a multiple of 9.