46
The numbers 15 and 16
Textbook Part 2, pp. 12–13
GoalBonds of 15 and 16; putting answers in order.
New words
fifteen · o‘n beshsixteen · o‘n oltiage (years) · yosh
Explanation
15 = 10 + 5 = 9 + 6 = 8 + 7. 16 = 10 + 6 = 9 + 7 = 8 + 8. We add the years between two events to find the total time.
Worked examples
A poplar was planted 10 years ago and a plane tree 6 years before that. The plane tree’s age: 10 + 6 = 16 years.
8 + 8 = 16 — another double.
Class activity
Leaf boxes: children put 15 or 16 leaf cards into boxes and count each box as a ten plus ones.
Practice
1
9 + 6 = ?
15
2
7 + 9 = ?
16
3
16 − 6 = ?
10
4
Fill in the number line: 12, 13, _, 15, _
14, 16