Getting around Singapore

By Taxi

http://www.yoursingapore.com/content/traveller/en/plan-your-trip/transport/travelling-within-singapore/taxi.html

http://www.lta.gov.sg/content/ltaweb/en/public-transport/taxis/getting-a-taxi.html

Rates as per the Singapore Transit Authority
http://www.lta.gov.sg/content/ltaweb/en/public-transport/taxis/fares-and-payment-methods.html
some surcharges may apply for airport and city central.

This is a very useful website called gothere.sg.  It shows the transit and taxi rates, with distance, routes.
For example from Innotel hotel on Orchard road to Changi Airport Terminal 1 is under $20 SGD and takes 24 minutes.
http://gothere.sg/maps#q:11%20penang%20ln%2C%20singapore%20238485%20to%20changi%20airport%20terminal%201

From the marina bay cruise terminal to Innotel on orchard road it is around $7 SGD and takes 11 minutes.
http://gothere.sg/maps#q:marina%20bay%20cruise%20to%2011%20penang%20ln%2C%20singapore%20238485

By Subway

http://www.yoursingapore.com/content/traveller/en/plan-your-trip/transport/travelling-within-singapore/mrt.html