10 .
What is the correct rule for multiplying by a whole number beginning with 1 and followed by one or more zeros, e.g. multiplying by 10, 100, 1,000, ... ?
When multiplying by such a number, move the digits to the left by the same number of zeros as in the number
When multiplying by such a number, move the digits to the right by the same number of zeros as in the number
When multiplying by such a number, move the digits to the left by the same number of digits as in the number
When multiplying by such a number, move the digits to the right by the same number of digits as in the number