Some Native American tribes made jewelry with Dentalia shells. Each Dentalia shell is about 1.5 inches long. About how much longer would a necklace made with 24 shells be than a necklace made with 18 shells? Use compatible numbers.

Answer-

The necklace with 24 shells is longer than the necklace with 18 shells by 9 inches.

Solution-

Length of each dentalia shell = 1.5 inches

Length of the necklace made with 24 shells = 24*1.5 = 36 inches

Length of the necklace made with 18 shells = 18*1.5 = 27 inches

The necklace with 24 shells is longer than the necklace with 18 shells by the amount of,

= 36 - 27 = 9 inches

∴ The necklace with 24 shells is longer than the necklace with 18 shells by 9 inches.

(∵ As the numbers are already rounded off or natural numbers, so we don't have to round them off or use the compatible numbers.)