Find the Missing Number
Aligned to 1.OA.D.8 — Common Core State Standards for Mathematics.
What this lesson teaches
Sometimes a number is missing in a math sentence. We find the number that makes both sides equal.
Worked example
5 + ? = 8. Think: 5 plus what makes 8? 5 + 3 = 8, so the missing number is 3.
Practice questions
- Find the missing number: 4 + ? = 7.
- Find the missing number: ? + 2 = 6.
- Find the missing number: 9 - ? = 5.
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Encuentra el número que falta
A veces falta un número en una oración de matemáticas. Buscamos el número que hace iguales los dos lados.
Ejemplo: 5 + ? = 8. Piensa: ¿5 más cuánto hace 8? 5 + 3 = 8, así que el número que falta es 3.
More Operations & Algebraic Thinking lessons
Adding and Subtracting within 201.OA.C.6Story Problems1.OA.A.1Adding Three Numbers1.OA.A.2Add in Any Order1.OA.B.3Subtract by Thinking Addition1.OA.B.4Counting On1.OA.C.5
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