Why do you start multiplying with the ones place when using regrouping to multiply

You serve 3 1/4 gallons of punch at a party. your friends drink 1 1 /2 gallons of the punch. which of these containers is the smallest you can use to store the remaining punch?

He mass of a single atom of carbon can be found by dividing the atomic mass (12.01 g) by 6.022 x 10^23. which is the mass of a single carbon atom, correctly written in scientific notation with the correct number of significant figures?

Find the least common denominator for thesetvo rational expressions.n^2/n^2+4n+4 -3/n^2+7n+10