Table 7: Nature of tasks selected during the Inquiry into Student Thinking assignment.

Problem type# of tasksPSTs exampleNumber choices

Join Change Unknown5“Joshua collects rocks. He likes to keep them in bags of ten. Last week he had a total of ____ bags. After finding some more this week, he now has ____ bags. How many rocks did Joshua find this week?”Number Choices: 5, 6) (5, 8) (8, 12) (9, 15)
Join Result Unknown8I would create Joint-Result-Unknown (JRU) or Separate-Result-Unknown (SRU) problems for the students. A JRU example would be “Sunny has ____ fish, and then she buys ____ more. How many fish does she have now?” Number choices would includeNumber Choices: {(10, 50) (20, 30) (10, 41) (15, 25)}.
Compare change unknown1Emilio had 64 soccer cards. Sunny had 28 soccer cards. How many more soccer cards does Emilio have than sunny?
Separate result unknown4Emilio has __soccer balls. __ Soccer balls roll away. How many Soccer balls are left?Number Choices: (15, 5) (26, 16) (57, 27) (81, 51)
Group size unknown2Jack has 65 pencils. He wants his 5 classmates to each have an equal amount of pencils. How many would each classmate get?”No number Choices
Number of groups unknown3Sunny has 94 chocolate chips. She needs 10 chocolate chips to make a cookie. How many cookies can Sunny make?No number Choices
Both product unknown & Joint Result Unknown4Sunny has 8 rolls of candy. Each package has 11 candies in it. She also has 12 extra candies. How many candies does she have in all?No number Choices
Product unknown and compare result unknown1Mary had __ bags of cookies with __ cookies in each bag and Amy had __ bags of cookies with __ cookies in each bag. Which one had more cookies?No number Choices
Relational thinking problems140 + 60 = - + -No number Choices
True/false sentences110 + 2 = 6.No number Choices
10 + 5 = 5 + 10
10 + 10+10 + 9 = 20 + 19