Aloha India, leader in advanced Abacus and Mental Arithmetic programs

This is your LEFT HAND... represents Unit

Now Let us practice the Finger Calculation (+) and ( - )
10+10=	20+20=	30+10=
90-20=	50-30=	80-30=

Exercise : Try it orally or by sight
(1) 10 + 30 - 40 (2) 20 + 10 - 20 (3) 30 + 10 - 20 (4) 50 + 20 - 10 (5) 90 - 60 - 30	(6) 80 + 10 - 90 (7) 40 - 20 + 60 (8) 70 - 50 + 20 (9) 60 - 10 - 50 (10) 20 + 20 + 70