Since all of the "number of things" words all follow the same pattern (number plus つ), you really just have to remember the part before the つ (and then remember that the つ is in all of these). All of the readings are the kun'yomi reading, which means we'll have to use a mnemonic to remember them (you know the on'yomi reading of the kanji portion).
What thing do you have nine of? The nine things that you have are nine coconuts (ここの). Imagine yourself juggling nine coconuts in the air. Try counting them while you're doing this, arriving at nine things.
There are nine questions that require a dictionary on today’s test.
Is it true that a cat has nine lives?
I made nine donuts.