New
New
Year 2

Count a large group of objects by counting tens and ones

I can count larger groups of objects efficiently using tens and ones to help me.

New
New
Year 2

Count a large group of objects by counting tens and ones

I can count larger groups of objects efficiently using tens and ones to help me.

Lesson details

Key learning points

  1. One item can be used to represent several other items. This is called unitising.
  2. The order in which tens and ones are arranged does not affect the value of the number.
  3. We can use a one hundred square to help find the value of two-digit numbers more efficiently.

Common misconception

Children may continue counting in tens when they reach the ones, e.g. count 2 tens and 3 ones completely in tens. They may think arrangement of tens and ones affects how to count them.

Make deliberate errors to prompt discussion and refer back to previous stem sentences, e.g. 'The objects are in ones, so I can count them in ones.' Present tens and ones in non-standard arrangements, so children practise always counting tens first.

Keywords

  • Unitising - Unitising means treating groups that contain, or represent, the same number of things as ‘ones’ or ‘units’. It is important in understanding place value and supports us to think multiplicatively.

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Which of the following describes the picture?
An image in a quiz
We have 4 groups of ten and 8 more ones.
Correct answer: We have 8 groups of ten and 4 more ones.
Q2.
Laura has put her cubes into groups of ten and has some more ones left over. Which place value chart represents her cubes?
An image in a quiz
Correct Answer: An image in a quiz
An image in a quiz
An image in a quiz
Q3.
How would you write the number eighty-nine in digits?
Correct Answer: 89
Q4.
Andeep has 54 straws. He puts them into groups of ten and there are some more ones left over. Which of the following could describe his group?
There are 4 groups of ten and 5 extra ones.
Correct answer: There are 5 groups of ten and 4 extra ones.
There are 9 groups of ten and no extra ones.
Q5.
Match the numbers that have the same value.
Correct Answer:73,7 groups of ten and 3 more ones

7 groups of ten and 3 more ones

Correct Answer:94,9 groups of ten and 4 more ones

9 groups of ten and 4 more ones

Correct Answer:37,3 groups of ten and 7 more ones

3 groups of ten and 7 more ones

Correct Answer:49,4 groups of ten and 9 more ones

4 groups of ten and 9 more ones

Q6.
Andeep counts his pencils in ones. He has 37 pencils. If he puts them into groups of ten, how many extra ones will he have left over.
3
Correct answer: 7
37

6 Questions

Q1.
Which of the following are true?
An image in a quiz
There are 6 groups of ten and 4 more ones.
Correct answer: There are 4 groups of ten and 6 more ones.
Correct answer: There are 46 ones.
There are 64 ones.
Q2.
Which place value chart matches the one hundred square?
An image in a quiz
An image in a quiz
Correct Answer: An image in a quiz
An image in a quiz
Q3.
Which of the following represents the same value as the one hundred square?
An image in a quiz
Correct answer: 74 ones
47 ones
84 ones
Q4.
Which of the following images represents the same value as the one hundred square?
An image in a quiz
An image in a quiz
Correct Answer: An image in a quiz
An image in a quiz
An image in a quiz
Q5.
Which of the following is true?
An image in a quiz
The number being shown is 65
Correct answer: The number being shown is 56
Correct answer: There are 5 tens and 6 ones
There are 6 tens and 5 ones.
Q6.
I’m thinking of a number which is on the one hundred square. It has more than 8 tens and it has 2 ones. What is my number?
Correct Answer: 92

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