Paper
Weller, J., Dieckmann, N. F., Tusler, M., Mertz, C. K., Burns, W., & Peters, E. (2013). Development and testing of an abbreviated numeracy scale: A Rasch Analysis approach. Journal of Behavioral Decision Making, 26(2),198212. doi:10.1002/bdm.1751
Want help coding the data for the scale?
Contact the Research Coordinator at <caide@osu.edu> for answers, instructions, example workbooks, and other materials.
Scale Update (02/2016)
Please note that the last two questions, 7. and 8., are well known on Mechanical Turk. Items from Toplak, West, and Stanovich (2014) have been used as substitutes for those questions when administering the scale on MTurk.
Toplak, M., West, R., & Stanovich, K. (2014). Assessing miserly information processiong: An expansion of the Cognitive Reflection Test. Thinking & Reasoning, 20(2), 147168.
Scale Update (06/2014)
Please note that we adjusted the list of accepted answers for most of the items. Many of these newly accepted answers include alternative formats to previously accepted answers. Further commentary is included in the additional material.
Scale Update (02/2013)
Please note that we adjusted the mammogram item on the numeracy scale to reduce guessing and improve the scale further (i.e., before the answer to the item was 1/2). There is evidence suggesting that when people do not know the answer to a probability judgment their answer is 1/2 or 50% (Fischhoff & Bruine de Bruin, 1999).
8Item Scale (updated 06/2014)
Please acknowledge the authors if you use this scale.
1. Imagine that we roll a fair, sixsided die 1,000 times. Out of 1,000 rolls, how many times do you think the die would come up as an even number?
Answer: _____
2. In the BIG BUCKS LOTTERY, the chances of winning a $10.00 prize are 1%. What is your best guess about how many people would win a $10.00 prize if 1,000 people each buy a single ticket from BIG BUCKS?
Answer: _____ people
3. In the ACME PUBLISHING SWEEPSTAKES, the chance of winning a car is 1 in 1,000. What percent of tickets of ACME PUBLISHING SWEEPSTAKES win a car?
Answer: _____
4. If the chance of getting a disease is 10%, how many people would be expected to get the disease:
Out of 1000
Answer: _____ people
5. If the chance of getting a disease is 20 out of 100, this would be the same as having a _____% chance of getting the disease.
6.Suppose your friend just had a mammogram. The doctor knows from previous studies that, of 100 women like her, 10 have tumors and 90 do not. Of the 10 who do have tumors, the mammogram correctly finds 9 with tumors and incorrectly says that 1 does not have a tumor. Of the 90 women without tumors, the mammogram correctly finds 80 without tumors and incorrectly says that 10 have tumors. The table below summarizes this information. Imagine that your friend tests positive (as if she had a tumor), what is the likelihood that she actually has a tumor?

Tested Positive 
Tested Negative 
Totals 
Actually has a tumor 
9 
1 
10 
Does not have a tumor 
10 
80 
90 
Totals 
19 
81 
100 
Answer: _____ out of _____
7. A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball. How much does the ball cost?
Answer: _____ cents
8. In a lake, there is a patch of lilypads. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half of the lake?
Answer: _____ days