Find each Expression mentally show the steps you used 5x39

Well i'm not sure what the perfect explanation to this answer is but you just multiply 39x5 so 5x9+5x3

I'm not sure if this is how your teacher wants you to do mental multiplication, but these are a couple of ways I would do it.

1. This is probably the "better" way - - notice that 5 * 39 is just like (5 * 40) - 5. From here:

(5 * 40) - 5

200 - 5

195

2. Another method you could use would be to divide 39 by 2 then multiply by 10. It works mainly because dividing by 2 is multiplying by 0.5. Then, multiplying by 10 moves the decimal over to the right. It's like breaking up the * 5. It would go like this:

(39 : 2) * 10

19.5 * 10

195

I provided two methods of solving, but either way, the solution is 195.