More Practice, Bigger Numbers

Two and a half million is 2.5 × 10^6. To write it in standard form, move the decimal point six places to the right. The first move uses the 5 after the point, and the other five moves fill with zeros: 2500000.

To compare two positive numbers in scientific notation, compare the exponents first. The first parts are both at least 1 and less than 10, so the number with the larger exponent is the larger number. For example, 2.5 × 10^6 is larger than 9.8 × 10^5, because 6 is larger than 5. If the exponents are equal, compare the first parts instead.

Calculators and programming languages write the same number as 2.5e6. The e stands for “times 10 to the power of”, so 2.5e6 means 2.5 × 10^6. You will see this form often.