Fast Math Tricks

I watched a video on YouTube called Fast Math Tricks. It was a very interesting video because I was never taught how to do this fast trick. It shows us how to multiply two digit numbers by each other. For example 43 * 21= _____. What you do is you multiply the two first numbers and then you multiply the last two numbers. It would look like 4*2=8 and then 3*1=3. You would set it up like 8_3. From there you would take the outside numbers which are 4*1=4 and then the inside numbers 3*2=6. After you do that you add 4+6=10. You take the 10 and put the 0 in the empty space of 8_3 making it 803. From there you add take the 1 and add it to the 9 making the final answer 903. I think that is a quick easy way to find out the answer to a two digit number. I know that you can’t always use calculators in class especially in the class that I’m currently in. You have to actually do long hand multiplication and it takes a lot of time and not many people want to take the time out to do the long hand math. Everybody is so used to using calculators. When it comes to this fast trick all you have to do is easy multiplication and adding to get the answer. When it comes to helping little kids learn multiplication I think that teaching this method would be easier for them. Sometimes long hand math can be hard to understand and there are always easy mistakes you can make. Not a lot of people even realize the little mistakes they can make until they get something back that was graded and find out the answer. I know that that has happened to me so many times and I always get so mad at myself because I know that if I just went through the question a little slower I would’ve got the answer correct. Easy multiplication was never a problem for me but when it came to a two digit number or more it became harder and harder. I always try to find easier ways to find the answer so that I don’t have to do so much work, but sometimes the more work you show the better the answer will come out and you’ll always get full credit. It is always easy to lose credit for not showing enough work but you can always get partial credit if you show work and just get the answer wrong. Partial credit is always an advantage because it gives the teacher a chance to give you at least some credit so you don’t lose full points. Teachers always look to see if you show work because it is very important in a lot of cases. This video was definitely interesting to me because I never was taught or showed that method of getting the answer to a question like that.