Calculate the value of seventy-eight 10p coins in pounds.

"Seventy-eight 10ps" means 78 coins, each worth 10 pence.

$$\text{Total pence} = 78 \times 10 \text{p} = 780 \text{p}$$

There are 100 pence in 1 pound (£). To convert pence to pounds, divide by 100.

$$\text{Total pounds} = \frac{780 \text{p}}{100 \text{p/£}} = \pounds 7.80$$

The value is $\pounds 7.80$.