PowerShell Core, 99 69 bytes
($a=$args)|%{"$s$a"
$a=$a|%{($p+$_)%10;$p=$_}|select -skip 1
$s+=" "}
-99 bytes thanks to @mazzy !
($a=$args)|%{"$s$a"
$a=$a|%{($p+$_)%10;$p=$_}|select -skip 1
$s+=" "}
-99 bytes thanks to @mazzy !