Multi-Digit Decimals, GCF/LCM, and Negative Numbers
Aligned to 6.NS.C.6 — Common Core State Standards for Mathematics.
What this lesson teaches
The number line stretches in both directions, so numbers below zero are negative and are useful for things like temperature or money owed. You can also find the greatest common factor (GCF) of two numbers and the least common multiple (LCM), and plot points in all four quadrants of a grid.
Worked example
Find the GCF of 12 and 18. Factors of 12 are 1,2,3,4,6,12 and of 18 are 1,2,3,6,9,18. The largest shared factor is 6.
Practice questions
- Which is colder, -3 degrees or 2 degrees?
- Find the GCF of 8 and 20.
- What is the least common multiple of 4 and 6?
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
Decimales de Varios Dígitos, MCD/MCM y Números Negativos
La recta numérica se extiende en ambas direcciones, por lo que los números menores que cero son negativos y son útiles para cosas como la temperatura o las deudas de dinero. También puedes encontrar el máximo común divisor (MCD) de dos números y el mínimo común múltiplo (MCM), y graficar puntos en los cuatro cuadrantes de una cuadrícula.
Ejemplo: Encuentra el MCD de 12 y 18. Los factores de 12 son 1, 2, 3, 4, 6, 12 y los de 18 son 1, 2, 3, 6, 9, 18. El factor común más grande es 6.
More The Number System lessons
Teach this lesson today
An AI tutor that guides with questions instead of just giving answers — all K–12 core subjects, every child in the family.
Start free — no card required