If they differ by two orders of magnitude, they differ by a factor of about 100. Two numbers of the same order of magnitude have roughly the same scale: the larger value is less than ten times the smaller value.

If you increase an order of magnitude, you are basically just multiplying by 10. If you decrease an order of magnitude, you are basically just multiplying by 0.1. Scientists and mathematicians use order of magnitude so they can make estimates of big numbers.

Examples. Order of magnitude is the quantity of powers of 10 that there are in a number, or the number of powers of 0.1 in a negative number. Order of magnitude is usually written as 10 to the n th power. The n represents the order of magnitude. If you raise a number by one order of magnitude, you are basically multiplying that number by 10.

In general, an increase of n orders of magnitude is the equivalent of multiplying a quantity by 10 n. Thus, 2,315 is one order of magnitude larger than 231.5, which in turn is one order of magnitude larger than 23.15. As values get smaller, a decrease of one order of magnitude is the same as multiplying a quantity by 0.1.