Hi,
Calculation is as following:
Each leaf has 48x10Gbps access ports, which gives 480Gbps of total bandwidth.
In order to have no oversubscription, you need 5x100Gbps uplink ports.
If you have one spine, then you can connect 6 leafs with no oversubscription.
With ovesubscrioption model, you can connect 32 leafs with 4,8:1 ratio, 16 leafs with 2,4:1 ratio, 8 leafs with 1,2:1 ratio.
In order to scale, you would need to add spines. With 2 spines you can connect 10 leafs with no oversubscription and so forth.
Regards,
Roman