Basic Calculation: 07

(1)  501² = [{(501 + 1) ÷ 2} x 1000] + 1² = [251 x 1000] + 001 = 251,001

(2)  502² = [{(502 + 2) ÷ 2} x 1000] + 2² = [252 x 1000] + 004 = 252,004 

(3)  503² = [{(503 + 3) ÷ 2} x 1000] + 3² = [253 x 1000] + 009 = 253,009 

(4)  504² = [{(504 + 4) ÷ 2} x 1000] + 4² = [254 x 1000] + 016 = 254,016

(5)  505² = [{(505 + 5) ÷ 2} x 1000] + 5² = [255 x 1000] + 025 = 255,025

(6)  506² = [{(506 + 6) ÷ 2} x 1000] + 6² = [256 x 1000] + 036 = 256,036

(7)  507² = [{(507 + 7) ÷ 2} x 1000] + 7² = [257 x 1000] + 049 = 257,049

(8)  508² = [{(508 + 8) ÷ 2} x 1000] + 8² = [258 x 1000] + 064 = 258,064

(9)  509² = [{(509 + 9) ÷ 2} x 1000] + 9² = [259 x 1000] + 081 = 259,081

(10)  510² = [{(510 + 10) ÷ 2} x 1000] + 10² = [260 x 1000] + 100 = 260,100

(11)  511² = [{(511 + 11) ÷ 2} x 1000] + 11² = [261 x 1000] + 121 = 261,121

(12)  512² = [{(512 + 12) ÷ 2} x 1000] + 12² = [262 x 1000] + 144 = 262,144