Question

The table below shows the thickness of coins. Coin Thickness quarter i millimeters 12 millimeters dime nickel millimeters penny 13 millimeters Hailey stacks a dime on top of a penny. She estimates the thickness of the two coins to be less than 3 millimeters. Write a symbol (, or =) in the box to make the statement true. Then use the statement to tell whether Hailey's estimate is correct. 12 + 12 + 1 Is Hailey's estimate correct?

Answer 1

A dime has a thickness of 1 7/20 mm and a penny has 1 1/2 mm.

Stacking both coins, we will have :

`1(1)/(2)+1(7)/(20)`

and we have the inequality :

`1(1)/(2)+1(7)/(20)\boxed{\text{ }}1(1)/(2)+1(1)/(2)`

Note that 1 7/20 is less than 1 1/2, so the inequality symbol is "<"

`1(1)/(2)+1(7)/(20)<1(1)/(2)+1(1)/(2)`

since 1 1/2 + 1 1/2 is equal to 3mm

Therefore, the thickness of stacking coins is less than 3mm

Hailey's estimate is correct (Yes)