ABACUS TEST - 1 worksheet featuring three sections of arithmetic exercises involving direct sums and complement sums.

Here are the step-by-step calculations and the final answers for the Abacus Test.

I. Direct Sums

*Rule: Add and subtract the numbers directly in each column.*

1. $3 + 1 - 2 + 5 = \mathbf{7}$
2. $4 + 5 - 3 - 5 = \mathbf{1}$
3. $2 + 1 - 3 + 5 = \mathbf{5}$
4. $3 + 5 - 2 + 1 = \mathbf{7}$
5. $4 - 3 + 5 + 1 = \mathbf{7}$
6. $5 + 3 - 6 + 1 = \mathbf{3}$
7. $1 + 5 + 2 - 7 = \mathbf{1}$
8. $3 + 5 - 8 + 2 = \mathbf{2}$
9. $2 + 2 - 3 - 1 = \mathbf{0}$
10. $3 + 5 - 6 + 1 = \mathbf{3}$

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II. +5 Complements Sums

*Rule: Use the "Small Friend" (complement to 5) when adding numbers that go over 5 but stay under 10. For example, to add 4 when you only have 1 bead up, you add 5 and subtract 1.*

1. $3 + 2 + 3 = \mathbf{8}$
2. $4 + 1 + 2 = \mathbf{7}$
3. $2 + 3 + 4 = \mathbf{9}$
4. $2 + 4 + 1 = \mathbf{7}$
5. $4 + 1 + 3 = \mathbf{8}$
6. $2 + 2 + 4 = \mathbf{8}$
7. $3 + 3 + 1 = \mathbf{7}$
8. $4 + 4 - 6 = \mathbf{2}$
9. $4 + 3 - 7 = \mathbf{0}$
10. $4 + 2 - 5 = \mathbf{1}$

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III. -5 Complements Sums

*Rule: Use the "Big Friend" (complement to 10) or mixed complements. This usually involves carrying over to the next column or using complex bead movements.*

1. $2 + 5 - 4 = \mathbf{3}$
2. $1 + 5 - 3 = \mathbf{3}$
3. $3 + 5 - 4 = \mathbf{4}$
4. $1 + 5 - 2 = \mathbf{4}$
5. $5 - 1 - 3 = \mathbf{1}$
6. $2 + 5 - 3 = \mathbf{4}$
7. $5 - 2 + 5 = \mathbf{8}$
8. $5 - 4 + 6 = \mathbf{7}$
9. $5 - 1 + 5 = \mathbf{9}$
10. $1 + 5 - 4 = \mathbf{2}$

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Final Answer:

I. Direct Sums:
7, 1, 5, 7, 7, 3, 1, 2, 0, 3

II. +5 Complements Sums:
8, 7, 9, 7, 8, 8, 7, 2, 0, 1

III. -5 Complements Sums:
3, 3, 4, 4, 1, 4, 8, 7, 9, 2