Abacus Lesson 26: Subtractions using complements of 10, 10's column

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43 - 19 (43 take away 19)
Start from left to right
Take away 1 in 10's column
Complement of 9 is 1, add 1 in 1's column, take away 1 in 10's column
Answer is 24

22 - 8 (22 minus 8)
Complement of 8 is 2, add 2 in 1's column, take away 1 in 10's column
Answer is 14

71 - 19 (71 take away 19)
Take away 1 in the 10's column
Complement of 9 is 1, add 1 in the 1's column, take away 1 in the 10's column
Answer is 52

93 - 35 (93 take away 35)
Take away 3 in the 10's column
Complement of 5 is 5, add 5 in the 1's column, take away 1 in the 10's column
Answer is 58

156 - 98 (156 minus 98)
Start from left to right
In the 10's column, complement of 9 is 1, add 1 in 10's column, take away 1 in 100's column
In the 1's column, complement of 8 is 2, add 2 in 1's column, take away 1 in 10's column
Answer is 58

Now do Worksheet 26

Abacus Lesson 26: Subtractions using complements of 10, 10's column

Acknowledgements: This is a summary of the HEV Project, Abacus lesson: Subtractions using complements of 10, 10's column