SOLUTION: A fourth-grade student devised the following algorithm for subtracting 84 - 27. 4 minus 7 equals negative 3 84

Algebra.Com
Question 805107: A fourth-grade student devised the following algorithm for subtracting 84 - 27.
4 minus 7 equals negative 3
84
- 27
-------
-3
80 minus 20 equals 60.
84
- 27
------
-3
60
60 plus negative 3 equals 57
84
-27
-------
-3
+60
-------
57
Thus the answer is 57. How would you respond as a teacher? Will this technique always work?

Answer by richwmiller(17219)   (Show Source): You can put this solution on YOUR website!
yes it will always work for 2 digits numbers
RELATED QUESTIONS

Find the following: 84°13' -... (answered by stanbon)
I have tried to simplify the following but I am not sure I have the correct answer. 1. (answered by stanbon)
Find the following ratios 1. Sin 13 degrees 2. Cos 84 degrees 3. Tan 27 degrees (answered by Alan3354)
You are given the following data. Number of Absences Final Grade 0 91 1 89 (answered by Fombitz)
a student received grades of 80, 85, and 76 on three exams. find the least grade that... (answered by rfer)
84°13'-... (answered by richwmiller,Alan3354)
Please double check my work to see if I did this right. Find each of the following 84°... (answered by Alan3354)
Consider the distribution of Grades in Dr. Smith's class: Gender Grade... (answered by stanbon)
what is the rule for adding and subtracting multipying and diving intergers . for... (answered by longjonsilver,sdmmadam@yahoo.com)