INDUCTION THERAPY (weeks 1-4): Patients receive initial induction therapy on days 1-14 prior to beginning the study. Patients then receive vincristine intravenously (IV) and daunorubicin hydrochloride* IV over 15 minutes on days 15 and 22; dasatinib orally (PO) once daily (QD) and prednisone PO (or methylprednisolone IV) twice daily (BID) on days 15-28; methotrexate intrathecally (IT) on day 29; and some patients receive methotrexate, hydrocortisone, and cytarabine IT on days 15 and 22. After completion of induction therapy, patients undergo bone marrow aspiration for evaluation of disease. Patients with M1 bone marrow and minimal residual disease (MRD) < 1% (standard-risk disease) proceed to block 1 consolidation therapy 1 week after completion of induction therapy or when blood counts recover (whichever occurs later). Patients with M2 or M3 bone marrow or MRD >= 1% (high-risk disease) proceed immediately to block 1 consolidation therapy, regardless of blood counts. Patients with clinically evident or biopsy-proven testicular leukemia at diagnosis that persists at the end of induction therapy undergo 12 fractions of testicular radiotherapy beginning within 4 days prior to starting block 1 consolidation therapy.