You can easily help them in experimenting, comparing and testing simple theories.
The best part of it is that none of this requires very sophisticated or very costly play devices. The activities you can provide for your toddler needs orientation in such a way that the toddler gets motivated and gets a hands-on science learning.
The popular activities to be grouped into different branches of scientific activities and many of them thoroughly enjoyed by my daughter.
My daughter would get super excited to see the water lily in the large water pots growing while others in the simple pots. Fruits collecting can be a major excitement and a hands-on experience from where the fruits come. Please to take your kids outdoor at least once a month. Oh, the touch me not plant gave my daughter a pure tactile enjoyment.