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Who am I? Number riddles
Joyful Mathematics: Chapter 13
GoalUse clues to find a secret number.
New words
riddle · a puzzle with cluesclue · a hint that helps usguess · say what you think
Explanation
A riddle gives clues. Use each clue to cross out numbers. I am between 20 and 25 and I have 3 ones. Only 23 has 3 ones among 21, 22, 23 and 24. So I am 23. Check your answer against every clue.
Worked examples
I have 6 tens and 2 ones. Who am I? I am 62.
I am between 25 and 30. I have 8 ones. I am 28.
If you put 4 more with me, you reach 20. I am 16.
Class activity
Secret number. Think of a number between 1 and 50. Give three clues, such as how many tens, whether it is before or after a number, and what its ones are. Let your family guess. Then swap places.
Practice
1
I am after 38 and before 40. Who am I?
39
2
I have 5 tens and no ones. Who am I?
50
3
I am between 70 and 75. My ones are 2. Who am I?
72
4
I am 3 more than 10. Who am I?
13
5
I am shown by the blocks. Who am I?
83