How does checking with addition compare with checking using estimation

Adding = Sum What are those kind of words for subtract divide and multiply? I am not for sure what they are called.

Insert, or = between the given pair of numbers to make a true statement. - |-11| - (-11)

A rectangular window has a length of 44 inches and a height of 60 inches, what is the units for the perimeter of the window

The copy machine in your office can produce 22,400 copies in 7 hours. How many copies can it produce in 21 hours?

I need the awnser to 1+1

Can you guys give me step by step on how to solve this ... ik the answer. "infinitely many solutions" I need the STEPS 5 + x - 12 = x - 7

A company's sales decreased by 8% this year, to $9015. What were their sales last year? (Round your answer to the nearest penny.) My answer was 9,736.2, but the correct answer was 9798.91. Could someone explain how did they get to 9798.91?

Find the difference (2ab+7a+1) - (8ab+9)

Use four 8's to make 8

Terri brought 1.74 meters of rope. Gracie brought 1.64 meters of rope. Who brought more rope