Question

9
4
-5
6
7




How to do this on abacus tool​

Answer 1

Answer:

Ans. 21

Step-by-step explanation:

9+4=13, big friend +10-6

13-5=8, big friend -10+5

8+6=14, combination +10-5+1

14+7=21, big friend +10-3

So 21 is the answer

Answer 2

Answer:

Answer is 21

Step-by-step explanation:

You can do it on calculater