Thursday, September 10, 2015

Math problems of the week: 7th grade Common Core-inspired problem vs. Singapore Math

I. From a sample 7th grade question from from Pennsylvania's revised PSSA tests:



II. From the Singapore Math 5A placement test, which tests readiness for the second half of the fifth grade curriculum:




II. Extra Credit:

Compare the two problems in terms of:

(1) how hard they are to follow verbally

(2) how hard they are to set up mathematically once you've figured out the verbal stuff

In answering (1), be sure to consider gratuitous difficulties like:

(a) how the information is organized
(b) confusing phrasing and ambiguity (e.g., did Ryan ride another portion of the distance at a fast speed for some purpose other than training?).

3 comments:

Anonymous said...

The answer to the Singapore question should be 128, not 108?

Auntie Ann said...

Abe has 108, Barry 81, Carlos 67.

Cassandra Turner said...

Anon: One way to solve with Singapore models...

A: [unit] [unit] [unit] [unit]
B: [unit] [unit] [unit]
C: [unit] [unit] [unit]-14

If you add 14 to C, he has the same as B, making 10 equal units.

256 + 14 = 270
10 units =270
1 unit = 270/10=27
A: 4 units = 27*4=108
B: 3 units = 27*3=81
C: 81-14=67