Estimate a 10% tip on a bill of $158.71 by first rounding the bill amount to the nearest ten dollars.

158.71 rounded to the nearest ten dollars would be $160.00

 then to estimate 10% since 10% starts with a 1, just remove the zero from both numbers

 so 160 becomes 16

 the tip would be $16

Step-by-step explanation:

Jayden sells 9 T shirts and 3 sweat shirts for $420. Carson sells 1 T shrit and 6 sweat shrits for $296. If this is adding then the answer is 716. I don't know your math very much I am in 4th grade. But I tried. : (