By giving children 2-7 years. Specifies whether there is a lot of water bottles?Step by step: first two bottles of water and refill. The second step is to enter the bottled water, the bottles one at a different shape.
The children aged 2-7 years indicates that bottled water is a good first step would be both water bottle and add water to equal the second stage water bottles to put another bottle of the same shape.
The children 2-7 years.Given that the bottle has a lot of water.The first step to water and water to fill both equally.The second stage water to put another bottle shape is different.