Categories
- Abbott and Costello (1)
- Addition (1)
- Ambiguity (1)
- Arithmatic (1)
- Auditory Patterns (1)
- Brain-teaser (1)
- Demography (1)
- Energy (1)
- Fractions (2)
- Geometry (2)
- Jokes (3)
- Logic (1)
- Machines (1)
- Math (16)
- Math Books (2)
- Math Dance (1)
- Math Education (4)
- Math Fun (3)
- Math Humor (9)
- Math Learning (3)
- Math Reasoning (2)
- Math Teaching (1)
- Math Video (2)
- Negatives and Positives (1)
- Numbers (1)
- Patterns (4)
- Physics (1)
- Physics Education (3)
- Precision (1)
- Probability (1)
- Reader's Digest (3)
- rhthym (1)
- Science (2)
- Science Education (3)
- Sets (1)
- Statistics (1)
- Subtraction (1)
- TED (3)
- Time (1)
- Topology (1)
- Uncategorized (6)
- Visual Patterns (1)
- Visualization (2)
- Wind Energy (1)
- Wind Power (1)
- World development (1)
- World Economy (1)
Latest Postings
- March 26, 2010: Math Is the Science of Patterns, Including This One
- March 10, 2010: When 15 > 25?
- February 22, 2010: Amelia's Dance = the Body as a Math Visual Aid
- February 22, 2010: Driving Math with the Math of Driving
- October 21, 2009: 10,000 Left Shoes
- June 12, 2009: Right on Time
- February 22, 2009: Mathematical Chuck Norris Facts
- February 21, 2009: Subtraction Without Borrowing
- February 12, 2009: Self-Reference in Musical Theater -- Show Off from Drowsy Chaperone
- February 9, 2009: Testing Probability
Links
Archives
Subtraction Without Borrowing
I have written a procedure for dynamic subtraction, in which borrowing is replaced by dynamic addition and the subtraction that has to be done is much simpler: it is done within each place-value column, in any order; that is, subtracting the single-digit numbers in each column is completely independent of anything you do in any of the other columns. You can read more about it iin the following sites:
- Simplified Procedure
- Original (light) Procedure
- PDF download of this original version
- Detailed Explanation (download a PDF file)
- Subtraction Without Borrowing (my article)