This is my usual go-to first aid when my baby’s tummy aches. But I have no idea what’s the other easy way if I ran out of the same?

Ru yi oil is what I would use for my kids tummy ache. This has been around for a really long time and is easily available in pharmacies and supermarkets in Singapore. It costs around $6 for a bottle. It's really effective and my kids will automatically ask for it if they are not feeling well in their tummy. Just put 1-2 drops in your palm and rub your palms together quickly. Then gently run your palms in a clockwise manner around your child's tummy. They should feel better in a few minutes.