Categories Numbers & Operations in Base 10 Subtraction Subtraction Mistake Post author By mpershan Post date November 8, 2012 2 Comments on Subtraction Mistake What’s the mistake? Why is it tempting? Thanks to Christopher Danielson for this submission. His blog. His twitter. Share this:EmailPrint ← Baseball Fields and Geometry → Division by Zero 2 replies on “Subtraction Mistake” The mistake is the missing negative sign on the 7 in the tens place. I often subtract like this: “five hundred negative seventy negative two, that’s four hundred thirty negative two, that’s four hundred twenty-eight.” Wow! That works! Comments are closed.