1. at the grocery store checkout, you watch at the register as it rings up your purchases and coupons. the prices were as follows: $2.95 $1.19 $4.61 $1.74 $3.04 $8.83 $1.16 – $0.75 (coupon) – $1.00 (coupon) the register gives your total bill as $21.77. estimate the total amount of the bill and use your answer to determine whether the total on the register is reasonable.

estimate  by rounded to the nearest dollars

2 +1 +5 +2 +3 +9 +1 =  $23

-2

23-2 = 21

 yes the amount is reasonable

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this