You write the digits "261", then add six zeros.
261,000,000 = 2.61 x 10^8
It is 2.61*10^2.
Two hundred sixty one (261) in standard form is: 2.61 × 102
261,000,000
261,000,000
2.61 written in fraction form is 261/100
261 million kilometers=162,177,881 miles
261,000,000
261% = 261/100 which cannot be simplified.
261,000,000
165/261 = 55/87
CCLXI
261/5 miles.