Squaring of numbers that end in 1 or 9

The trick is to multiply the whole numbers on the either sides of the number that you are squaring and then add 1.

Have fun with the trick

212 = 441

As the number to be squared ends in 1.

  • Multiply the two whole numbers on the either
    sides of 21.

    20 x 22 = 440

  • Add 1 to 440440 + 1 = 441
Let’s try one more:

192 = 361

As the number to be squared ends in 9.

  • Multiply the two whole numbers on the either
    sides of 19.

    18 x 20 = 360

  • Add 1 to 360360 + 1 = 361

Time for you to try

112 =
512 =
312 =
392 =
292 =
992 =