Represent a number from 20 to 99 | Maths | Quizalize & Oak National Academy

Starter quiz

Which of the following describes the picture?

We have 6 groups of ten and 3 more ones. ✓

We have 3 groups of ten and 6 more ones.
Which of the following is true?

There are 5 groups of ten and 3 more ones.

There are 3 groups of ten and 5 more ones. ✓

There are 35 ones. ✓

There are 53 ones.
Which of the following represents the same value as the one hundred square?

53 ones ✓

35 ones

57 ones

37 ones
Which representation matches the place value chart?
I’m thinking of a number which is on the one hundred square. It has seven tens and more than six ones. Which of these numbers could I be thinking of?

56

75

78 ✓

79 ✓
I’m thinking of a number which is on the one hundred square. It has 6 ones and fewer than 3 tens. Which of these numbers could I be thinking of?

36

63

26 ✓

6 ✓

Exit quiz

Which representation matches the number on the chart correctly?
What do you notice about all of these numbers? 35 36 37 38

They are all odd numbers.

They all have the same ones digit.

They all have the same tens digit. ✓
What do you notice about all of these numbers? 35 45 55 65

They are all even numbers.

They are all greater than 40

They all have the same ones digit. ✓
Laura is counting forwards in ones on her Gattegno chart. Which representation shows the number she will tap next?
Jun has these Base 10 blocks. Which of these numbers could he make?

42

34 ✓

15

22 ✓
True or False? 62 is the only number that can be made using 8 Base 10 blocks .

True
False ✓

Worksheet

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Lesson Details

Key learning points

The order in which tens and ones are arranged does not affect the value of the number.
We can use the patterns in numbers to help us represent new numbers.

Common misconception

When representing two-digit numbers practically, children may start each number anew, instead of using what they know about number patterns to adapt existing representations.

Use the questions 'What's the same?' and 'What's different?' to draw attention to the patterns in number sequences and how these can be used. Link the abstract to the pictorial and concrete by drawing attention to what each digit represents.

Keywords

Two-digit number - A digit is a single symbol used to make a numeral. A two-digit number uses two symbols to make one numeral.
Tens digit - The symbol used to represent the number of tens in a numeral.
Ones digit - The symbol used to represent the number of ones in a numeral.