Ensure you go to The Orchid Garden in Botanic. I'd get there as it opens and walk in the opposite direction to "the arrows".
I see in the post below you may be a senior?
If you keep your passport with you, many places offer over 60's from any country decent discounts for entry. From recall for example Botanic gardens is reduced from S$5 to S$1.
Definitely a senior - 65+ - at least in most places. Will a driver's license with a picture and date of birth work as well as a passport (I don't like to carry my passport around)? FWIW - a fair number of senior discounts in Singapore seem to apply only to citizens and permanent residents (over 60). Which makes sense to me. Robyn