Buying some things

This task is about working out change from buying things.

Some friends each saved up $15 and went shopping.

Question

a) Select all the things that costs under $15.

b) Aleisha bought 2 things with her $15.

She got $5 change.

Select the 2 things she bought.

c) Sandra bought 2 things with her $15.

She got $3 change.

Select the 2 things she bought.

d) Geena bought 3 things with her $15.

Select the 3 things she bought.

		Y4 (11/2013)
a)	Ticks Poster, Teddy bear, Pen and Photo frame and no others	very easy
b)	Ticks Teddy bear and Pen and no others	easy
c)	Ticks Poster and Photo frame and no others	moderate
d)	Ticks Poster, Pen and Photo frame and no others	moderate

	Common error	Likely reason	Next steps
c)	Ticks Teddy bear and Pen (gives a total of $7.00)	Close reading error The student misreads question as getting change from $10 rather than $15	Get students to read the question again carefully taking note of all elements of the problem.
d)	Ticks Teddy bear, Pen and Photo frame (gives a total of $15.50)	Place value error: recombining decimals or whole numbers Students do not "carry" the $1 from the three lots of $0.50 and gets an answer of $14.50	Get students to work with playmoney coins and notes. They should recombine two lots of 50 cents into $1. If they also fail to recombine the ones and tens, use $1 and $10 notes. Also: Ask the students to find three items that do cost less than a total of $15.