Subtract by Thinking Addition

Aligned to 1.OA.B.4 — Common Core State Standards for Mathematics.

What this lesson teaches

To subtract, we can ask what number we add to reach the bigger number.

Example 1

10 - 8 = ? Think: 8 plus what makes 10? 8 + 2 = 10, so 10 - 8 = 2.

Example 2

13 − 9 = ? Think: 9 plus what makes 13? 9 + 4 = 13, so 13 − 9 = 4.

Example 3

Every subtraction hides an addition. Because 6 + 5 = 11, you already know 11 − 5 = 6 and 11 − 6 = 5.

Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.

Para restar, podemos preguntar qué número le sumamos para llegar al número más grande.

Ejemplo 1: 10 - 8 = ? Piensa: ¿8 más cuánto hace 10? 8 + 2 = 10, así que 10 - 8 = 2.

Ejemplo 2: 13 − 9 = ? Piensa: ¿9 más cuánto hace 13? 9 + 4 = 13, así que 13 − 9 = 4.

Ejemplo 3: Cada resta esconde una suma. Como 6 + 5 = 11, ya sabes que 11 − 5 = 6 y que 11 − 6 = 5.

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