Use multiplication except with the ones place "1"
Write down the numbers from 1000 to 9999.
solution: we know that there are 25 prime numbers are between 1-100 and 168 prime numbers less than 1000. 100 x 100=10000(5 digits) 999 x 999=998001(6 digits) 1000 x 1000=1000000(7 digits) so our answer should be same as the number of prime numbers between 100 to 999. hence, 168-25=143. 143 prime numbers will be there less than 1000 whose square has 5 or 6 digits.
10001
16
91.
4*5*5*5 = 500
Numbers above 99 and under 1000 are 3-digits, all 900 of them.
123
Not couting 1 and 1000, there would be 998 numbers.
Write down the numbers from 1000 to 9999.
solution: we know that there are 25 prime numbers are between 1-100 and 168 prime numbers less than 1000. 100 x 100=10000(5 digits) 999 x 999=998001(6 digits) 1000 x 1000=1000000(7 digits) so our answer should be same as the number of prime numbers between 100 to 999. hence, 168-25=143. 143 prime numbers will be there less than 1000 whose square has 5 or 6 digits.
10001
16
252 of them.
91.
Thousands would be your 4 digit numbers - 1000-9999.
998 - 3 digits even number Next even number is 1000 - 4 digits. So 998 is the largest ...