Toys is an obvious topic to select for infants. Not only is it appealing , at least initially, it is also one where you can find a good range of artefacts. Investigating these objects helps not only in Art and Science but also in Design and Technology. The important point to remember is that it is a better vehicle for looking at ‘old and new’ and ‘then and now’ than it is for looking at change through time. As such I would always teach it in Year 1 not Year 2. I would also not teach it for too long. Because it is a good cross-curricular topic involving most subjects there is a tendency to make it a term long when perhaps it need not be.
I would suggest that you can cover the main history points in about 5 hours. Spending longer runs the danger of boring some children and taking time from other possible topics where there is more action and more scope to develop a wider range of historical skills.
Toys old and new knowledge organiser – KS1 - You are learning about old toys to help you to understand the difference between toys people played with 
