1
Sixteen to twenty
Joyful Mathematics: Chapter 4
GoalCount and read the numbers 16 to 20 as ten and some more.
New words
sixteen, seventeen · 10 and 6; 10 and 7eighteen, nineteen · 10 and 8; 10 and 9twenty · 10 and 10; two tens
Explanation
Start with a full ten. Add 6 more. That is sixteen. 10 and 7 is seventeen. 10 and 8 is eighteen. 10 and 9 is nineteen. 10 and 10 is twenty. Twenty is two tens. 20 is one more than 19.
Worked examples
10 and 7 is 17 (seventeen).
10 and 9 is 19 (nineteen). One more makes 20.
10 and 10 is 20 (twenty). Two full frames.
Class activity
Counting steps. Put 20 steps or chalk marks on the ground. Walk along them and count out loud from 10 to 20. Then walk back from 20 to 10. Clap on 15 and clap again on 20.
Practice
1
How many counters are there?
18.
2
How many counters are there?
15.
3
10 and 8 is what number?
18.
4
What comes after 19?
20.
5
What is 1 less than 20?
19.