MA118 Mathematics I
Name_______________________________
Worksheet—3.3 Algorithms for Adding and Subtracting Whole Numbers
Addition Algorithms—Be sure you can clearly explain your thought process with all of the methods.
Make exchanges with mats, strips and units—Draw diagrams clearly indicating how exchanges are made with mats,
strips and units to determine the answer to the following problems.
1. 387  294
2. Find the sum of 132 and 378
What are advantages and disadvantages of using this method?
What are your feelings about this method?
Place Value Diagram—Clearly indicate how a place value diagram can be used to find the following sums.
3. 423  512
4. 113  245
What are advantages and disadvantages of using this method?
What are your feelings about this method?
Partial Sum Algorithm (our text calls it the instructional algorithm)
Use the left-to-right partial sum algorithm to find the following sums.
5. 583  139
6. 983  257
Use the right-to-left partial sum algorithm to find the following sums.
7. 184  29
8. 345 186
What are advantages and disadvantages of each of the above methods?
What are your feelings about this method?
Scratch Method—Use the scratch method to find the following sums.
9. 843  979  236
10. 945  23  179  346
What are advantages/ disadvantages of the scratch method?
What are your feelings about the method?
Traditional Algorithm—Find the following sums, using the traditional method. Completely explain how exchanges are
made?
11. 589 132
What are advantages/ disadvantages of the traditional method?
Compare the addition algorithms.
12. 892  465
Subtraction Algorithms—Be sure you can clearly explain each method.
Make exchanges with mats, strips, and units—Draw diagrams clearly indicating how exchanges are made with mats,
strips and units to determine the answer to the following problems.
13. 568  329
14. 932  639
What are advantages/disadvantages of this method?
What are your feelings about this method?
Place-Value Diagram—Clearly indicate how a place value diagram can be used to find the following differences.
15. 558  236
16. 545  258
What are the advantages/ disadvantages of using a place-value diagram?
What are your feelings about this method?
Partial Sum (or Instructional Algorithm)—Use the partial sum algorithm to find the following differences.
17. 845  64
18. Subtract 156 from 228
What are advantages/disadvantages of using the partial sum algorithm?
What are your feelings about this method?
Low Stress Subtraction Algorithm—Find the difference using the low stress subtraction algorithm.
19. 587  368
20. 538  289
What are advantages/disadvantages of this method?
What are your feelings about this method?
Equal Additions Algorithm—Find the difference using the equal additions algorithm.
21. 4576  3689
What are advantages/disadvantages of this method?
What are your feelings about this method?
22. 1923  876
Subtraction by adding the complement—Find the following difference by adding the complement. Carefully explain
why this method works.
23. 4824  678
Traditional Algorithm—Use the traditional method to find the following differences. Completely explain how the
exchanges are made.
24. 238 129
25. 468 179
What are advantages/disadvantages of the traditional method.
What are your feelings about this method?
Compare the subtraction algorithms.