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 20 more blue stickers than green stickers.
He has 40 more red stickers than
the sum of  the number of blue and green stickers.

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

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

Number of green stickers = 1 u
Number of blue stickers = 1 u + 20

Number of green and blue stickers
= 1 u + 1 u + 20
= 2 u + 20

Number of red stickers
= 2 u + 20 + 40
= 2 u + 60

Number of more red stickers than green stickers
= (2 u + 60) - 1 u
= 2 u - 1 u + 60
= 1 u + 60

(b)
Number of less blue stickers than red stickers
= (2 u + 60) - (1 u + 20)
= 2 u + 60 - 1 u - 20
= 2 u - 1 u + 60 - 20
= 1 u + 40

(c)
Number of blue and red stickers
= 1 u + 20 + 2 u + 60
= 1 u + 2 u + 20 + 60
= 3 u + 80

Answer(s): (a) 1u + 60 ; (b) 1u + 40; (c) 3u + 80