Write 3E+5 in decimal notation.

Step 1: Since 3 do not have a decimal point, we will add one at the end of the number 3.

3.

Step 2: The exponent for 10 is 5. Since the exponent is positive, we must move the decimal point of a number 3. 5 places to the right.

3. → 3.-----.

Step 3: Now we just need to replace empty spaces (dashes) with zeros and to delete old decimal point (the black one) to get:

300000