Page 148 - NUMINO TG_4A

09Door Frame Method Unit

Material Calculator

Use the following steps to find a Kaprekar number. Have the students use the method shown to
identify if each number is a Kaprekar Number.
What you need: calculator
After completing this page, students will find
3,025 that the Kaprekar Number are 3,025,
2,025, and 9,801.
1. Split a 4-digit 2. Add the two 3. Multiply the sum
number into 2-digit from step 2 by itself.
two groups of If the answer is the
2-digit numbers. same as the original
numbers. number, we call it a
Kaprekar number.

30 25 30 + 25 = 55 55 55 = 3,025

2,025 5,025

20 25 = 45 50 25 = 75
45 45 = 2,025 75 75 = 5,625

5,801 9,801

58 01 = 59 98 01 = 99
59 59 = 3,481 99 99 = 9,801

9. Door Frame Method 81

There is also an 8-digit number that is a Kaprekar Number. This number was discovered by J. A. H. Hunter
and is 60,481,729.

6,048 1,729 7,777
7,7772 60,481,729

4A Unit 09 131