3. Eric filled 3/4 buckets with sand. Then he filled
472 more. How many buckets of sand does he
have now?

Am I supposed to add or subtract

  472 3/4

Step-by-step explanation:

Consider the meaning of "one, and one more". That does not mean zero (1-1). Rather, it means two (1+1).

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Then 3/4 and 472 more is ...

Eric has 472 3/4 buckets filled with sand.

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The problem statement here seems to be focused on the filled buckets, rather than the sand stockpile that Eric is working from. The amount in that stockpile is being reduced by the amount that is being used to fill buckets. In short, whether you add or subtract depends on what you're trying to figure.

step-by-step explanation: