Maria has $5.00 more than Joseph. Together they have $37.50. Which of these equations would you use to find the amount of money Joseph has?
A. j + (5 x j) = $37.50
B. j + ( j ÷ 5) = $37.50
C. 5 x j = $37.50 + j
D. 2 x ( j + 5) = $37.50
E. j + j +5 = $37.50
This item ... is missed by the majority of eighth-grade students in the NWEA norm group.
The Proficiency Illusion
John Cronin, et al
October 2007
I'm going to guess C. would get this right.
We'll see.
Of course, this is a classic bar model problem in Singapore Math. Third grade level, I believe, although you don't use variables. Still, the bar model is as abstract as a letter variable, or close to.
As a teacher of physics and a stickler for equations with correct units, I would say none of the answers is correct. But I would give partial credit for E.
ReplyDelete