A construction worker bought 21 7/8

Let's use equivalent decimals.

21.875 * 2.5 = _______ pounds

21 7/8 * 2 1/2

one way is to use distributive property

(21 + 7/8)(2 + 1/2)

=(2 + 1/2)(21) +(2 + 1/2)(7/8)

= 42 + 21/2 + 7/4 + 7/16

= 42 + 168/16 + 28/16 + 7/16

= 42 + 203/16

= 42 + 12 + 11/16

= 54 11/16

If your teacher wants to keep it in fractions...

Convert 21 7/8 into an improper faction of 175/8 and 2 1/2 into 5/2. Multiply together and reduce/ convert to mixed fraction of 54 11/16.

You get 54 11/16 but the thing I don't know is that if you multiple you get the answer and if you divide you get the answer

Since the problem says "2 1/2 times" you are going to multiply. If you are getting the same answer dividing, you are dividing incorrectly. My guess is that you are not flipping the second fraction before multiplying when you are dividing (to divide fractions, you flip the second fraction and multiply).

What are you multiplying? What is the answer?

What are you dividing? What is the answer?

multiplying by 5/2 should not give the same answer as multiplying by 2/5(which is dividing by 5/2)

In the answer choices I get both of the answer if you multiple 21 7/8 and 2 1/2 you get 54 11/16 and if you divide 21 7/8 and 2 1/2 you get 8 3/4

Jenny -- which answer makes sense to you?

She bought more than twice as many nails the second time.

Did she buy over 54 pounds or almost 9 pounds the second time?

Many times, the author of an assignment will include common mistakes as answer choices. You then need to check your answer by making sure it makes sense. If she buys more than twice as much as she did the first time, will the answer be greater than or less than the amount she bought the first time?