Regroup to express the number in a different way. \begin{aligned} 16{,}590=& 1 \text{ ten thousand} + 6 \text{ thousands} + 5 \text{ hundreds} + 9\text{ tens} 16{,}590=& 1 \text{ ten thousand} + 6 \text{ thousands} + 4 \text{ hundreds} + \bigstar\text{ tens} \end{aligned} 16,590= 16,590= 1 ten thousand+6 thousands+5 hundreds+9 tens 1 ten thousand+6 thousands+4 hundreds+★ tens