Answer:
1.98 × 10^10
Explanation:
First solve for how many text messages were sent out per one month:
22,000,000 × 900
19,800,000,000
Convert into scientific notation:
1.98 × 10^10
In scientific notation, there can only be one number before the decimal. The rest of the numbers must be after the decimal; hence, why I put the numbers 9 and 8 after the decimal. If the rest of the numbers are zeros, you do not have to add them after the decimal. Instead, starting from right to left, count the number places until you reach your decimal. The number you have counted will be your exponent. I counted nine 0's, one 8, and one 9 which made this exponent 10 as there were 10 decimal placements.