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Multiplying by 2
Textbook: Part 3, lesson 91, pp. 42–43
GoalKnow the multiplication table for 2.
New words
table · jadvalpair · juftnumber line · sonli nurcounting in twos · ikkitalab sanash
Explanation
The 2 times table comes from counting in twos: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20. Each product is 2 more than the one before. 2 × 6 = 12 and 6 × 2 = 12, because factors can swap places.
Worked examples
2 × 4 = 8, 2 × 7 = 14, 2 × 9 = 18.
8 pairs of children: 8 × 2 = 16 children.
Class activity
“Pairs”: children stand in pairs. The class counts aloud 2 × 1, 2 × 2, 2 × 3 ... and says how many children there are in total.
Practice
1
2 × 9 = ?
18
2
7 × 2 = ?
14
3
Children in a dance club lined up in pairs. There are 8 pairs. How many children are in the club?
16
4
Solve: x − 12 = 2 × 9. x = ?
30
5
Solve: y + (2 × 4) = 52. y = ?
44