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

Adam, Charlie and Bryan have some marbles.
After Adam's number of marbles is doubled,
Charlie's number of marbles is increased by 6 and
Bryan's number of marbles is reduced by 3,
the ratio of the number of stickers of Adam to Charlie to Bryan becomes 2 : 3 : 2.

Let the number of stickers that Bryan has in the end be 2 u.

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

	Adam	Charlie	Bryan
Before	1 u	3 u - 6	2 u + 3
Change	x 2	+ 6	- 3
After	2 u	3 u	2 u

(a)
Change information into units.

Number of marbles that Adam has at first
= 2 u ÷ 2
= 1 u

(b)
Number of marbles that Charlie has at first = 3 u - 6

(c)
Number of marbles that Bryan has at first = 2 u + 3

(d)
Total number of marbles that they have at first
= 1 u + 3 u - 6 + 2 u + 3
= 1 u + 3 u + 2 u - 6 + 3 
= 6 u - 3

Answer(s): (a) 1 u; (b) 3 u - 6; (c) 2 u + 3; (d) 6 u - 3