Sophia wrote odd numbers on her paper. What is a number Sophia did not write

2.5 milligrams is equivalent to how many grams

Cal's go cart has a gas tank with the dimensions shown below. he uses a gas can that holds 11 gallon of gas, to fill the go cart tank. 11 gallon = 231 inches^3 how many full gas cans will it take to fill the go cart's gas tank?

Ribbon a is 1/3 meters long. it is 2/5 meters shorter than ribbon b. what's the total length of 2 ribbons?