I need help with 7 and 8, Round and/or estimate then add (nearest hundred) for both attachment below

The perimeter of the rectangle is 120 feet. if the length of the rectangle is ten feet more than the width ,what are the dimensions (length and width) of the rectangle?

Miguel has 334 baseball cards and 278 football cards. he says, i have 612 cards in all. is that reasonable? explain using the words round and estimate.

Stephanie runs three days a week. she ran 3 2/3 miles on monday , 4 1/5 miles on wednesday , and 2 2/9 miles on friday. how many miles did she run this week ?