Answer:
6.6×10²¹
Step-by-step explanation:
6,600,000,000,000,000,000,000 → there are 21 place values after the first non-zero number ''6''
to convert to standard form, we move the decimal point after the first non-zero number.
6,600,000,000,000,000,000,000.0 ← decimal in the end
the decimal will be moved, all the digits after the decimal are counted and they will resemble the index.
6.6×10²¹
