 manavudu calculator vale vaegamgaa ankaganita ganananu elaa chestad ?
 mentally abacus aney saanketikatanu upayoginchandi .  ooka vyakti sankhyalanu chadivinappudu ,  athanu ledha aama maanasikangaa abacus ‌ nu drushyamaanam chessi ,  abacus ‌ loni puusalanu kadilinchadam dwara ganana chestaaru .  ganana goppa vaegamtho cheyavachu .