Dominosa or Domino Solitaire is a logic puzzle with a similar feel to Sudoku. Given a grid of numbers, you have to lay out the dominoes so they match the numbers, without duplicated or missing dominoes. It was invented by O.S. Adler in 1874. It seems that Puzzling.SE doesn't have any standard Dominosa problems, and I just finished adding Dominosa to Donimoes, my collection of domino puzzles and games, so I thought I would post a few bonus problems here.
As a warm up, here's a tiny example with all the dominoes from double blank to double two.
Try it yourself, then check your answer here:
Here's a slightly larger problem with all the dominoes from double blank to double four.
If you like this puzzle, watch for more challenging problems later in the week.