(Please read through, I'm sorry it looks a bit long but it's mostly because of the way I typed the problems out)
Okay, so the formula to find the circumference of a circle is "2* π* r". In this case,
π = 3.14
r = 7 (radius of the circle)
So, the equation is:
2 x 3.14 x 7
(I'm using x for multiplication symbol)
First, multiply 2 x 3.14 To do this, line the numbers up like so:
3.14
x 2
----------
And multiply each digit of the first number (3.14) by two, making sure to account for the 0s after it. Example, if the number is the 1 in 3.14, you would actually be multiplying 2 x 10, because that would have a 0 after it if the 4 wasn't in the way. Likewise, 3 would be 300 because those two numbers are in the way. (The decimal point is not counted as a place.) Then, each time you multiply, write the number below, like this, making sure to keep them aligned (forgive the askew alignment):
3.14
x 2
----------
8
20
600
Now, you add up the numbers:
600
20
+ 8
-------------
628
For the final step, count the numbers behind the decimal point on the right side. In this case:
3.14
2
Which equals 3. Now start at the far right of your final number, and count the number of spaces that there are numbers. (3 in this case, sorry that's confusing) and you have where your decimal point goes.
. 6 2 8
(It's easier to show being drawn, but I hope you get the point.)
And there is your finished number is decimal form. I'm terribly sorry if any points were confusing or not properly explained, I have trouble in math myself but I recently relearned this and thought I would try and help because I struggled with this as well. Research on your web browser if you need further explanation. I also apologize if this is too late for you to use the answer.