Summary of "SUMA Y RESTA DE NUMEROS ENTEROS MÉTODO DEBO Y TENGO Super facil - Para principiantes"

Brief summary

Use the “I have / I owe” method to add and subtract integers: treat positive numbers as money you have and negative numbers as money you owe. The instructor color-codes positives blue (“I have”) and negatives red (“I owe”) and uses worked examples to show how debts and assets combine.

Main ideas and concepts

Positive numbers (> 0) represent “I have” (assets).
Negative numbers (< 0) represent “I owe” (debts).
If a number has no sign, assume it is positive.
When combining integers:
- Same sign: add absolute values and keep the common sign (two debts become a larger debt; two assets become a larger asset).
- Different signs: subtract the smaller absolute value from the larger absolute value; the result takes the sign of the number with the larger absolute value.
Visual aids (coloring positives blue and negatives red) help track which amounts cancel or combine.

Step-by-step method (detailed)

Identify the sign of each integer.
- If no sign is shown, treat the number as positive.
Label each number:
- “I have” for positives (blue), or
- “I owe” for negatives (red).
Group numbers by sign (same-sign group and opposite-sign group).
If all numbers share the same sign:
- Add their absolute values and attach the common sign to the sum.
If numbers have different signs:
- Subtract the smaller absolute value from the larger absolute value.
- The result takes the sign of the number with the larger absolute value.
State the final answer as either “I have X” (positive) or “I owe X” (negative).

Worked examples

30 − 10
- 30 (I have) and −10 (I owe) → 30 − 10 = 20 → I have 20
+20 − 50
- 20 (I have) and −50 (I owe) → difference 50 − 20 = 30; larger is negative → I owe 30 (−30)
−64 + 54
- −64 (I owe) and 54 (I have) → difference 64 − 54 = 10; larger is negative → I owe 10 (−10)
−17 − 83
- Both negative (I owe 17 and I owe 83) → add: 17 + 83 = 100 → I owe 100 (−100)
75 − 35
- 75 (I have) and −35 (I owe) → 75 − 35 = 40 → I have 40