Question

What is the total number of digits required in numbering the pages of a book, which has 1,724 pages?

Answer 1

5,789

Explanation:

we know that

When numbering the pages of a book, which has 1,724 pages, we need:

9 one-digit numbers (from 1 - 9)

90 two-digit numbers (from 10 - 99)

900 three-digit numbers (from 100 - 999)

725 four-digit numbers (from 1,000 - 1,724)

Multiply each value by the number of digits

so

`9(1)+90(2)+900(3)+725(4)\\9+180+2,700+2,900\\5,789\ digits`