David Marain over at MathNotations has been periodically tweeting an SAT problem of the day via @dmarain. A recent series of tweets asked:

A 42 oz mix of nuts is 6 parts peanuts to 1 part cashews. How many ounces of cashews must be added to make a make the mixture 2 parts cashews to 1 part peanuts?

Does Singapore (bar) model method work here?

Sure it can! Here’s one solution.

*First model the beginning mixture at 6:1.*

*Next, we can figure out how many units need to be added to the cashews to make the cashews to peanuts ratio 2:1. *

*Since there are 11 additional units and the value of each unit is 6 oz, we can find the value of the added cashews.*

** 66 ounces of cashews must be added to the peanuts to make the mixture 2:1.**

Changing Ratios is taught in level 6A in the Primary Mathematics materials (U.S. Edition)**,** typically used in 6th grade classrooms.