Fill in the blanks.
For (a) to (c), give the answers in units (Eg 1 u) or unit equations (Eg 1 u + 2).

Adam has some stickers.
He has 10 more red stickers than green stickers.
He has 100 less blue stickers than
the sum of the number of red stickers and green stickers.

1. How many more blue stickers than green stickers are there?
2. How many less blue stickers than red stickers are there?
3. How many red and blue stickers are there?

(a)
Choose the smallest group to be 1 u.

Number of green stickers = 1 u
Number of red stickers = 1 u + 10

Number of green and red stickers
= 1 u + 1 u + 10
= 2 u + 10

Number of blue stickers
= 2 u + 10 - 100
= 2 u - 90

Number of blue stickers more than green stickers
= (2 u - 90) - 1 u
= 2 u - 1 u - 90
= 1 u - 90

(b)
Number of blue less than red stickers
= (1 u + 10) - (2 u - 90)
= 1 u + 10 - 2 u + 90
= 10 + 90 + 1 u - 2 u
= 100 - 1 u

(c)
Number of red and blue stickers
= 1 u + 10 + 2 u - 90
= 1 u + 2 u + 10 - 90
= 3 u - 80

Answer(s): (a) 1 u - 90; (b) 100 - 1 u; (c) 3 u - 80