3 ms·
That is a horribly complicated way to do 17 + 35. The sane way is to try matching against a pattern, then if that fails you fall back to the traditional algori
by tropo 11y ago
That is a horribly complicated way to do 17 + 35.
The sane way is to try matching against a pattern, then if that fails you fall back to the traditional algorithm with the numbers lined up one over the other and doing the carries. Yes, you can run the traditional algorithm in your head, for this and for much larger things. Fully in memory, 4-digit plus 4-digit is quite doable. (can your method handle that?) While staring at the numbers on paper to avoid forgetting, and writing down the answer as you go, arbitrary sizes are doable.
It so happens that I do see a pattern I can fit, but this shouldn't be expected. I convert to 17+(172+1) and then to 173+1 and I know 17*3 is 51 so the answer is 52. It's forgivable to not spot this shortcut.
- deleted 11y ago[deleted]
- pflats 11y ago>(can your method handle that?) It's not "my" method. I'm not quite sure what I did to merit attitude and hostility, but to answer your question: Yes. Third-graders are expected to do it with 3-digit numbers. You'll have to take my word for it that I'm capable of adding 4-digit numbers. http://www.corestandards.org/Math/Content/3/NBT/#CCSS.Math.Content.3.NBT.A.2 http://www.corestandards.org/Math/Content/3/NBT/#CCSS.Math.C...
- tropo 11y agoWhat hostility? Come on, you have to admit that a procedure which expands the problem out to the sum of 5 numbers is pretty insane. BTW, my shortcut got mangled by Hacker News. Multiplication turned into italics. I did 17 times 3, which is great, but I don't think that anybody should be expected to see that path to a solution.