I don't get it. At all. HELP!! ¤Ð-¤Ð 😭

Jenna lives 4 3/10 miles from school. She estimates that she travels 4¡¿2¡¿5, or 40 miles each week. Is her estimate an overestimateor an underestimate? EXPLAIN!!!!

Right -- but I'd estimate it about 43 miles per week.