Answer:
Yes
Step-by-step explanation:
Yes,the area is the space inside a shape. If we change the borders of the shape, in space in the interior will change.
I don't quite understand the ten strategy, or what EXACTLY you're asking. But, what you can do is when you add a one digit number plus a nine, just change the nine to a ten and subtract one. It is very easy. So, 7+10 equals 17, subtract one and you get 16 which is 7+9. It is always one less than anything plus 10.
