Multiply them by their reciprocal.
For example, suppose you start with five eighths. Multiplying by eight fifths makes it 100 per cent.
5/8 * 8/5 = 1 = 100%.
3.875 = 3 and eight hundred seventy five thousandths percent
Two eighths of anything is 25% of it.
12.5
87.5%
62.5
25%
hfuiygokl
87.5%
25%
87.5%
12.5%
37.5 percent