There is no number sentence
Some of these, I don't know how to answer. I can only give the answers to the ones I do know how to do.
16. 24 plants can be watered with this can.
Equation & Answer:
134.4 ÷ 5.6 = 24
17. 32 miniature bottles can be made from the large bottle of ketchup.
Equation & Answer:
198.4 ÷ 6.2 = 32
20. -3 + -8 = -11
-3 + 8 = 5
3 + -8 = -5
-9 + 4 = -5
-6 + -1 = -7
-8 + 9 = 1
Negatives plus negatives:
When there are two negative numbers together and the equation has + sign in it, the + sign changes to be a - sign.
21. 42 + -56 = -14
22. -49 + -17 = -66
Hope this helped in some way,
-Anime
As far as I can tell, is referring and assuming the ruler doesn't have any fractional values, namely it only has markings with integers.
so in short is asking, what are the two integers that the fractional 5¼ is between?