+14 The units digit of both numbers are \(3\) and \(7\), so \(3\cdot7 = 21\), where the units digit is \(1\). The units digit of \(13\cdot287\) is \(\boxed{1}\)
+14 Or did you mean to find the units digit of \(13^{287}\)? It's a bit more complicated but still doable.
