Question

Jacinta is working on a jigsaw puzzle that has 403 pieces. She has completed 1/4 of the puzzle. About how many pieces has she placed in the puzzle

Answer 1

$403 / 4 = 100.75$ 
to get any fraction of a number, as long as the numerator is 1 in the fraction, just divide by the denominator. In this case it's 4. Since you can't place .75 of a puzzle piece, she's placed 100 pieces in the puzzle.