Ineed solving this problem for mental math strategies for multiplication and the problem is 7×312=7×(_+_)

12 300

Step-by-step explanation:

The way that I would do this, is first doing 7*300. That would result in 2100.

Next would be doing 7*12. Resulting in 84.

Finally you would add 2100 and 84 which is very simple just 2184.

If 300 looks like a tough number to multiply, just do 7*3 then add two 0's to the end.

e.

step-by-step explanation:

because there are always 10 numbers in a phone number.