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Sixty-one to eighty
Joyful Mathematics: Chapter 8
GoalRead, say and write the numbers from 61 to 80.
New words
seventy · the name for 7 tens, written 70eighty · the name for 8 tens, written 80tens word · the first part of a number name
Explanation
Six tens make 60, sixty. Seven tens make 70, seventy. Eight tens make 80, eighty. We say the tens word first, then the ones. 6 tens and 3 ones are sixty-three. 7 tens and 6 ones are seventy-six.
| Tens | Number | Name |
|---|---|---|
| 6 tens | 60 | sixty |
| 7 tens | 70 | seventy |
| 8 tens | 80 | eighty |
Worked examples
6 tens and 7 ones make sixty-seven.
| Tens | Ones | Number |
|---|---|---|
| 7 | 4 | 74 |
Sixty-one to eighty on the number grid. The tens end at 70 and 80.
Class activity
Circle count. Sit in a circle. Start at 61. Each child says the next number in turn, going round. Stop at 80. Start again, but count back from 80.
Practice
1
Look at the blocks. Which number is this?
72
2
Write seventy-six as a number.
76
3
What number is 8 tens?
80
4
What comes just after 69?
70
5
What comes just before 80?
79