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Thirty-six to thirty-nine
Discover Mathematics: Chapter 6
GoalCount 36 to 39, write them, and see that 39 is one less than 40.
New words
thirty-six · three tens and six onesthirty-nine · three tens and nine onesforty · four tensone less · the number just before
Explanation
After 35 we say 36, 37, 38, 39. Each of these numbers has three tens. The ones are 6, 7, 8 and 9. Thirty-nine has three tens and nine ones, which is one less than forty. When we add one more to 39, the ones make a new ten, and we get four tens. That number is forty, written 40.
Worked examples
Hamza shows 36 with sticks and cubes: 3 sticks and 6 cubes.
Farida has 38 sweets in a jar: 3 tens and 8 ones.
Ziad counts 39 stars. One more star would make four tens.
Class activity
Clap and count. Count aloud from 30 to 40, clapping on each number. At 40 jump once. Then count backwards from 40 to 30 slowly. Ask: which number comes just before 37, and just after 38?
Practice
1
How many tomatoes are there?
36
2
What number comes before 38?
37
3
How many fish are there?
39
4
What number is one more than 39?
40
5
Write the number for 3 tens and 7 ones.
37