2
Twenty-six to twenty-nine
Discover Mathematics: Chapter 5
GoalCount up to 29, write 26 to 29, and see each one as two tens and some ones.
New words
twenty-six · two tens and six onestwenty-seven · two tens and seven onestwenty-eight · two tens and eight onestwenty-nine · two tens and nine ones
Explanation
After 25 comes 26. We add one more each time: 26, 27, 28, 29. All of these numbers have two tens. Only the ones grow: 6 ones, then 7, then 8, then 9. When we write them, the 2 for the tens comes first and the ones come next. Twenty-nine is nearly three tens. One more than 29 starts a new ten.
Worked examples
Ziad counts 26 oranges at the market stall: two rows of ten and 6 more.
Laila picks 28 flowers in the garden: 2 tens and 8 ones.
Habiba packs 29 bananas. With one more banana she could fill a third row of ten.
Class activity
Number steps. Write 26, 27, 28 and 29 on four paper squares and put them on the floor in a mixed-up order. The child puts them in order, then hops from one to the next and says each number aloud. Hide one square and ask: which number is missing?
Practice
1
How many fish are there?
27
2
What number comes before 28?
27
3
How many kittens are there?
29
4
Which is more, 24 or 29?
29
5
Write the number for 2 tens and 8 ones.
28