Directions: I picked 3 dominoes out of a bag and they all had exactly 10 pips, but the same number was not on both sides of any of the dominoes.

Show 3 dominoes I could have picked.

### Hint

### Hint

If one side of the domino had 8 pips, how many pips were on the other side if I had 10 pips altogether?

If one side of the domino had __ pips, how many pips were on the other side if I had 10 pips altogether?

### Answer

### Answer

0 and 10

1 and 9

2 and 8

3 and 7

4 and 6

1 and 9

2 and 8

3 and 7

4 and 6

Source: Brian Kelley

I like this idea, but these solutions do not match what actual dominoes look like.

Hi Janet. I guess their are bigger sets of dominoes than we realized. I thought you were right but wanted to verify and I found this: https://www.amazon.com/Double-Color-Dot-Dominoes-Game/dp/B001D4MIZM/. So apparently these are possible answers.

Yes there are larger sets of dominoes, but typically up to double 6 or double 9 are standard for game-playing. Some cultures will likely have more familiarity with domino games using certain sets (I have mostly played games with double six sets and rarely with double 9 sets).

So depends what students were introduced to before.

For a double 6 set the only solution is the 4:6.

For a double 9 set the other solutions (except the 0:10) come into play.

For a double 6 set, 7 might be a nicer number (1:6, 2:5, 3:4) to start with initially.