Cogito
Grade 3 Math · Chapter 3 · Lesson 2
Multiplying by 6
Double the threes.
10 problems · about 12 minutes · 3.OA.C.7, 3.OA.B.5
What this lesson teaches
The child recalls the 6 times table and derives it from the 3 times table.
- A six is two threes, so double the three fact.
- Or use the five fact and add one more group.
- The division facts come with them.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
2 problemsReview — Breaking an Array Apart: 7 × 8 = ?
Answer 56
Why 40 + 16 = 56.
Review — Litres and Millilitres: How many millilitres are in one litre?
Answer 1000
Why 1 litre = 1,000 ml.
Warm Up
Straightforward practice. Get the method working first.
4 problems9 × 6 = ?
Answer 54
Why 9 × 6 = 54.
How can you build a six fact?
Answer Double the matching three fact.
Why Doubling the three fact gives the six fact.
4 × 6 = ?
Answer 24
Why Double 12.
6 × 6 = ?
Answer 36
Why Double 18.
Build It Up
The same ideas with more to keep track of.
2 problems8 × 6 = ?
Answer 48
Why Double 24.
42 ÷ 6 = ?
Answer 7
Why What times 6 makes 42?
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
2 problemsThe Egg Boxes: 7 boxes each hold 6 eggs. How many eggs?
Answer 42 eggs
Why 7 × 6 = 42.
The Insects: 9 insects each have 6 legs. How many legs?
Answer 54 legs
Why 9 × 6 = 54.