take number 1000 and then add 20 to it . now add 1000 one more time . now add 30 . now add 1000 one more time . now add 40 . now add 1000 one more time . now add 10 . what is the total ?
a 4100
add(add(add(add(1000, 1000), 1000), 1000), add(add(add(20, 30), 40), 10))