Take a $50 bill and look at the back of it. Do you see a pair of gibbons swinging through vines?

Most Singaporeans will have missed the painting by the late Chen Wen Hsi, one of Singapore's pioneer artists. Ms Zita Chu, 39, who has used the money for years, had no clue they were there.

Yesterday, the electronics trader had to race through the Singapore Zoo with other Marsiling-Yew Tee residents to snap a picture of the primates.

The challenge was part of a grassroots event to help new citizens, permanent residents and foreigners integrate into Singapore society.

They were paired up with two Singaporeans in teams of four to track down the gibbons. Ten teams took part in the event.

Ms Chu, who has lived in Singapore for eight years and became a Singapore citizen in 2012, never noticed the monkeys previously.

"I didn't know they were gibbons, this is something new I learnt today," said the former Shanghai resident.

Ms Chu's teammate Roger Tan, 57, said activities and games like those yesterday are a good way for new citizens to integrate.

"We want them to not only integrate, but also get to know their neighbours," said the sales engineer.

Yesterday's event also featured a carnival where the residents tried local games such as carom, five stones and capteh, and sampled local snacks like kacang puteh and muah chee.

The event was attended by 1,200 residents and Marsiling-Yew Tee GRC MPs, including Minister for National Development Lawrence Wong and Speaker of Parliament Halimah Yacob.

In his speech, Mr Wong said it was important to recognise that Singapore was a country of immigrants.

"Some of us are old immigrants, because our grandparents, our great-grandparents came from overseas... all of us have roots from other countries, but then over time, we become Singaporean," he said.

He urged new citizens to make an effort to fit in, and understand Singaporean norms and cultures. At the same time, he told Singaporeans to be welcoming.

Speaking to the media, Madam Halimah said these community events allowed people to get to know new citizens and stop seeing them as competition for homes, jobs and school places.

"You begin to see that everybody is a Singaporean, everybody has got family, everybody has got their hopes and their aspirations."