I calculated it in my head without memorising all the multiplication tables. I just realised that 7*3.5 is equal to (7*5+7*2)/2. And that 49/2 is equal to 40/2+9/2. Easy peasy. This is why I failed second grade math, because multiplication tables are only useful for doing operations a few seconds faster.
I calculated it in my head without memorising all the multiplication tables. I just realised that 7*3.5 is equal to (7*5+7*2)/2. And that 49/2 is equal to 40/2+9/2. Easy peasy. This is why I failed second grade math, because multiplication tables are only useful for doing operations a few seconds faster.
There’s a much easier way.
7x3.5 is the same as 7x3 plus half of 7. That’s 21 plus 3.5 is 24.5
The funny thing is you did this for the division when you could do it for the entire thing.