Fill in the blanks in units (Eg 3 u) or unit equations (Eg 1 u + 2).

Charlie, Adam and Bryan have some stickers.
After Charlie's number of stickers is doubled,
Adam's number of stickers is increased by 9 and
Bryan's number of stickers is reduced by 3,
the ratio of the number of stickers of Charlie to Adam to Bryan becomes 10 : 3 : 1.

Let the number of stickers that Bryan has in the end be 1 u.

1. Number of stickers that Charlie has at first = _____
2. Number of stickers that Adam has at first = _____
3. Number of stickers that Bryan has at first = _____
4. Total number of stickers that they have at first = _____

	Charlie	Adam	Bryan
Before	5 u	3 u - 9	1 u + 3
Change	x 2	+ 9	- 3
After	10 u	3 u	1 u

(a)
Change information into units.

Number of stickers that Charlie has at first
= 10 u ÷ 2
= 5 u

(b)
Number of stickers that Adam has at first = 3 u - 9

(c)
Number of stickers that Bryan has at first = 1 u + 3

(d)
Total number of stickers that they have at first
= 5 u + 3 u - 9 + 1 u + 3
= 5 u + 3 u + 1 u - 9 + 3 
= 9 u - 6

Answer(s): (a) 5 u; (b) 3 u - 9; (c) 1 u + 3; (d) 9 u - 6