math

There are a total of 6,142,720 seven-digit numbers that can be made using digits 0, 1, 4, 6, 7, 8, and 9 that are less than 1,048,000. This is because each of the seven digits is independent of the others and can have any of the 6 possible digits we have, so 6 multiplied by itself seven times will be the number of possible seven digit numbers that can be made. That is, 6^7 = 6 x 6 x 6 x 6 x 6 x 6 x 6 = 6,142,720.