Question

Devon is buying 3 greeting cards that cost $0.97 each. How can rounding be used to estimate the total cost of the cards?

Since each card is about $1, the total cost is approximately 3 + 1 = $4.
Since each card is about $1, the total cost is approximately 3 x 1 = $3.
Since he is buying about 10 cards, the total cost is approximately 10 x 0.97 - $9.70.
Since he is buying about 10 cards, the total cost is approximately 10+ 0.97 = $10.97.

Answer 1

The second answer, Since each card is about $1, the total cost is approximately 3 × 1 =$3