The problem sets are derived from 8 different skills/topics--some from 2nd, and the rest from 5th grade.
TARGET STUDENTS: gifted classes, gifted individual students, students who want extra challenges, extra credit, end-of-semester challenge, summer camps, math clubs, elective math classes, etc.
FOUR worksheets are provided: one with 5 problems per skill; one with 10 per skill; one with 15 per skill and one with 20 per skill. You decide which is best for you. Each one has an answer key.
SEVEN quizzes (all with 10 problems each) are provided: TWO at a level 2 (not too hard); TWO at levels 2 and 3 (harder); TWO at level 3; ONE at levels 3 and 4 (potentially the hardest).
Further, look at the PREVIEW as it is typical of the actual offerings here.
[The problems in All WORKSHEETS and PREVIEWS are printed in difficulty (1 [easy], 2 [not so easy], 3 [proficiency] up to 4 [mastery]) order within a skill. The actual difficulty level appears slightly to the left of the DK box of each problem in a very small font.]
You might also want to check out the Domain Summary
and LEVEL 4 (challenging) questions
for the NBT Domain.
Also, check out the many other items I have (and will be adding to) for grades through 5--grades covered by the NBT Domain.