Write each number in scientific notation
First write out the whole number (3,500,000). Next focus only on the last non-zero number on the left (3), and put a decimal point after it (3.500,000). Next count the number of places to the right of the decimal point you just added. In this case there are six places. The answer, in scientific notation, is 3.5 x 10^6, or 3.5 times 10 to the 6th power.
3,500,000 = 3.5 × 106