### Instruction: What is the greatest possible number of digits in the product of a 4-digit whole number and a 3-digit whole number?### Response: I need to find the largest possible product of a 4-digit whole number and a 3-digit whole number, and then count how many digits it has.
To get the largest possible product, I want to maximize both factors.
The largest 4-digit whole number is 9999, and the largest 3-digit whole number is 999.
So the largest possible product is 9999 times 999.
I can use the distributive property to multiply 9999 by 999: 9999 times 999 equals 9999 times (1000 - 1) equals 9999 times 1000 minus 9999 times 1.
9999 times 1000 is 9999000, which has 7 digits.
9999 times 1 is 9999, which has 4 digits.
To subtract 9999 from 9999000, I need to align the digits and borrow from the left.
9999000 minus 9999 is 9989001, which has 7 digits.