From the pattern, we can say that the difference between the squares of two consecutive numbers is the sum of the numbers itself.
In a formula:
Using this formula, we get:
(i) 1002 − 992 = (99 + 1) + 99
= 199
(ii) 1112 − 1092 = 1112 − 1102 + 1102 − 1092
= (111 + 110) + (110 + 109)
= 440
(iii) 992 − 962 = 992 − 982 + 982 − 972 + 972 − 962
= 99 + 98 + 98 + 97 + 97 + 96
= 585