In a Winning Wednesday quiz about fractions and decimals, students are tasked with solving problems such as arranging 26 students at tables of four and interpreting this as 6½ tables used. They also explore equivalent fractions and decimal conversions, confirming that 7/10 equals 0.7 and demonstrating that 3/5 does not. Additionally, the teacher explains rounding numbers and determining whether a shape is divided into equal parts, emphasizing that less than one quarter is shaded when the shape is not evenly divided.