How do you keep active five-and six-year-olds away from one another? Or ensure the masks they have to wear stay on?
These have been among the biggest concerns of pre-school operators and teachers over the last week, ahead of the return to classrooms on Tuesday.
The answer some have come up with: Do not force the children to follow the rules, but teach them about the pandemic and explain why the safe measures are necessary.
At MapleBear centres, teachers call the coronavirus "Virus-C", which is easier and more fun for children to remember, and tell them masks are "shields against the Virus-C".
NTUC First Campus' My First Skool is starting a 30-day challenge when school reopens to encourage children to take small steps in learning good habits in personal hygiene, and rewarding them with daily stickers, while PAP Community Foundation (PCF) Sparkletots is creating picture books and card games related to Covid-19.
On Tuesday, Kindergarten 1 and 2 children - about 75,000 of them, according to previous figures - will return to school. Those in Nursery 1 and 2 will follow suit from June 8, while children in infant care and playgroup can go back from June 10.
In total, around 180,000 pre-school children, as well as 30,000 pre-school and early intervention staff, will return. But it will not be classes as usual.
At PCF centres, each teacher will manage only up to two classes, and staff cannot eat in groups to minimise contact, said Ms Marini Khamis, senior director of PCF's pre-school management division.
Instead of principals walking through the centres, they will observe through closed-circuit television, she added.
Pre-schools have also suspended the daily shower for all children to minimise close contact. Children are showered only when needed - such as when they have spilled food on themselves - or are given a wipe-down instead of a full shower.
"The changes require staff to adjust how they interact with the children," Ms Khamis said.
"For instance, they need to practise safe distancing themselves, while reinforcing daily practices through giving children stickers, or appointing older children as 'safe distancing' heroes."
Ms Thian Ai Ling, general manager of NTUC First Campus' My First Skool, said that mother tongue language teachers who used to teach at several centres will now stay put at one centre.
"They will use a digital platform to teach children at the second centre," she said.
Even within each centre, teachers will try to minimise contact with children as far as possible. MapleBear chief executive Patricia Koh said if children are feeling upset, teachers will try "safe" ways to comfort them.
"We don't always have to hug them at the first instance. Sometimes, children are easily distracted... We can ask them to look at the sky or play with bubbles and they may forget why they were crying," she said. "But we have to play it by ear as well. Caring for the child is our priority."
At nap time, cots will be placed 1m apart. Children will bring their own bedding to and from the centres, added Mrs Koh.
Mr Poh Soon Tat, head of operators at Star Learners, said there will be a limit of four children at each table during mealtimes. Combined areas will have markers indicating a 2m distance between groups.
Signs will be used to indicate where children can sit or stand.
Ms Thian said: "We don't want to frighten them with all these new habits. Instead of pasting big red crosses like at the hawker centres, we use cartoons."
Dr Jacqueline Chung, senior principal and academic director of St James' Preschool Services, which runs St James' Church Kindergarten and Little Seeds Preschool, said: "Many activities like outings have been suspended so we are looking at how to redesign these activities so we don't lose the essence of the social and emotional connection with the children."
For instance, outdoor play could be simulated indoors using virtual projections of settings like a forest, and children can role play, said Ms Cara Lee, deputy academic director at St James' Preschool Services.
She added: "Maybe we can't have goodie bags or birthday cakes anymore, and parents can't come into the centres, but there are other ways to make moments special for children, such as by getting parents to record a video clip to be played in school."
On Tuesday, more than 400,000 students, from primary schools to junior colleges, will also be going back to school.
Face-to-face classes will start on Tuesday for the Primary 6, Secondary 4 and 5 cohorts, while those from other batches - Primary 1 to 5 and Secondary 1 to 3 - will rotate weekly between home-based learning and lessons in school.
There will be a long list of rules to follow, such as wearing masks or face shields except when eating or exercising, and having a wipe-down routine after each lesson.
Teachers will take similar precautions, said Ms Liew Wei Li, director of schools at the Ministry of Education. Teachers will also use portable microphones or the classroom audio system, so they can be heard without raising their voices.
But for students, after two months of missing their friends, what is to stop them from mixing outside of school premises?
Jing Shan Primary is placing teachers on patrol duty in the immediate neighbourhood after dismissal. They will remind pupils to go straight home and not loiter, said principal Sharon Siew.
Parents share similar concerns.
Mr Adrian Wee, 43, a self-employed handyman who has a Secondary 2 daughter and a Primary 6 son, told The Sunday Times he plans to pick his children up from school, as opposed to their usual routine of taking public transport home, so they can avoid mingling with friends.
How schools are preparing to reopen
1 Help children to understand and adhere to safe practices
At MapleBear, which has about 3,000 pre-schoolers across 40 centres, teachers have come up with fun ways such as games to help them understand and adhere to safe practices such as social distancing.
"It's difficult to tell children they can't sit at a certain place. We aren't going to focus on the negatives, like 'Don't do this, or don't do that'," said MapleBear chief executive Patricia Koh. Instead, teachers will try to educate the kids, she said.
Teachers have prepared chairs with children's names on them, and when the kids return to the centres from Tuesday, they will be told to look for the specific chair with their names on it.
If they have to sit on the floor, mats with interspaced shapes such as circles, triangles and squares will be used and children can choose the shapes they like.
2 Staggering arrival and dismissal times
Pre-school operators will stagger the arrival and dismissal times for hundreds of children, to thin out the crowds at their centres.
Ms Marini Khamis, senior director of PAP Community Foundation's (PCF) pre-school management division, said some centres will open slightly earlier or later so that parents have a longer window in which to drop off and pick up their children, rather than one set timing.
PCF is the largest pre-school operator in Singapore with over 40,000 children. Other centres will split children into two groups and assign them staggered arrival timings.
Similarly, Ms Thian Ai Ling, general manager of NTUC First Campus' My First Skool, which has about 20,000 children, said: "We know the work patterns of parents across different centres. Principals have engaged parents to ask if they can come a bit earlier or later, so they don't have to wait to hand over the kids during health checks."
In addition, where possible, centres, and typically the larger ones, will designate specific entry and exit points for different levels of children, to minimise mixing.
3 Thorough cleaning by professionals
Ms Rabiatul Adawiah, chief development officer at Busy Bees Asia, which runs several pre-school chains such as Learning Vision, Pat's Schoolhouse and Small Wonder, said cleaning is being done on two levels.
Professional cleaners were called in to carry out disinfection across all the centres, while some staff had also returned for additional cleaning and preparations such as placing markers on the floor and tables as part of safe distancing measures.
Similarly, at Star Learners, the centres have thoroughly cleaned and disinfected premises, materials and resources.
Its head of operations Poh Soon Tat said it has engaged professional sanitisation misting services and installed air purifiers in every centre.
4 Meals in school
Some schools have asked children to bring their own food from home, while others are getting students to pre-order food from the canteen.
Jing Shan Primary School principal Sharon Siew said pupils are encouraged to bring packed food from home for recess, which will help to reduce intermingling as they can stay in the classroom instead of going to the canteen to buy food.
At National Junior College, instructions were given in a circular for student representatives on how to consolidate orders, pay for and pick up packed food from the school canteen for their classmates, as well as how to clean up after eating.
Meanwhile, at Crescent Girls' School, students have also been encouraged to bring food from home where possible.
For those who are unable to do so, a bento set system will be set up, with orders delivered from the canteen to the classrooms, where recess and lunch breaks are to be held.