21 and 20
992
679 is the product of the largest single-digit prime number and the largest two-digit prime number.
10,000,000 is the smallest 8 digit number 99,999,999 is the largest 8 digit number
The largest 8-digit number is 9,999,999.
21 and 20
992
No. When adding the smallest 2 digit number (= 10) to the smallest 2 digit number (again, 10) the result is a 2 digit number (10 + 10 = 20). When adding the largest 2 digit number (= 99) to the largest 2 digit number (again, 99) the result is a 3 digit number (99 + 99 = 198). As you can see, you'll either get a 2 or 3 digit number, but never a 4 digit number.
999 is the largest 3-digit number.
9797 is the largest two digit prime number.
679 is the product of the largest single-digit prime number and the largest two-digit prime number.
10,000,000 is the smallest 8 digit number 99,999,999 is the largest 8 digit number
The largest 8-digit number is 9,999,999.
The largest 4 digit number is 9999.
9 and 99
The largest 10-digit number with no digit repeated is 9876543210 !
The smallest 4-digit number is 1000, and the largest 4-digit number is 9999.