There are at least eight different ways to subtract multi-digit numbers. Even though a person has learned one method, it is good to explore other methods to enhance understanding. If a child has an accurate and efficient method of subtraction, do … [Read more...] about Dr. Cotter on Subtraction Approaches
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Dr. Cotter on What 6 × 3 Means
Sometimes 6 × 3 is thought of as “6 groups of 3.” However, consistency with the other arithmetic operations requires a second look. When adding 6 + 3, we start with 6 and transform it by adding 3. When subtracting 6 – 3, we start with 6 and transform … [Read more...] about Dr. Cotter on What 6 × 3 Means
Dr. Cotter on Long Division
As far as long division is concerned, it no longer has the importance it had in past generations. No one today spends time on their job doing long division. Long division with that guessing component is not used higher mathematics. It is rarely on … [Read more...] about Dr. Cotter on Long Division
Dr. Cotter on Multivides
For a child with learning disabilities doing multivides, I suggest this shorter version: Start with any 4-digit number and multiply it by 4, then 5, and 6. Then divide the final product by 4, then 5, and 6. The final quotient must be the same as … [Read more...] about Dr. Cotter on Multivides
