Final answer:
Fabrizio used 12.18 kilograms of flour in those 3 weeks.
Step-by-step explanation:
To convert grams to kilograms, we use the conversion factor 1 g = 0.001 kg. In this case, Fabrizio used 580 grams of flour each day for 3 weeks.
First, we need to calculate the total number of grams of flour used in 3 weeks by multiplying the grams used each day by the number of days in 3 weeks: 580 g/day * 7 days/week * 3 weeks = 12,180 g.
To convert grams to kilograms, we divide the total number of grams by 1000: 12,180 g / 1000 = 12.18 kg.
Therefore, Fabrizio used 12.18 kilograms of flour in those 3 weeks.