Always get the right answers with track & edit. New! Error proof. Wrong entry? No need for re-dos. Just track & edit. Track & edit up to 79 entries. Dual power. The TrackBack calculator with 2-line display combines the editing capability of spreadsheets with the simplicity of calculators. Maintain your sanity and forget re-doing long and complicated calculations after a mistake. The TrackBack lets you check up to 79 entries for verification and corrections. See what you entered. Visit us on - Facebook; Twitter; YouTube; Instagram. datexxinc. www.datexx.com. Made in China.