Students who demonstrate that they can read, write (type), make, order and interpret numbers to 1000 can be described as being able to work with 3-digit numbers. Experiences must include numbers containing one or more zeros.
Before achieving this, students have developed fluency working with 2-digit numbers through activities requiring reading, writing (typing), making, interpreting and ordering. Understanding may be consolidated when the pattern of digits becomes more predictable in the numbers following 20.
Through exploring 3-digit numbers in this same way, students begin to understand the pattern of groups of three that is the basis of the decimal place value system, ie 1, 1 ten, 1 hundred; 1 thousand, 10 thousand, 100 thousand etc.
Support students to use grouping partitioning and re-arrangement to apply place value and extend the range of numbers they use and apply to thousands
Recognise, model, represent and order numbers to at least 1000 (VCMNA104)
VCAA Sample Program: A set of sample programs covering the Victorian Curriculum Mathematics.
VCAA Mathematics glossary: A glossary compiled from subject-specific terminology found within the content descriptions of the Victorian Curriculum Mathematics.
Students count to and from, and order numbers up to 1000. They perform simple addition and subtraction calculations, using a range of strategies. They find the total value of simple collections of Australian notes and coins.
Students represent multiplication and division by grouping into sets and divide collections and shapes into halves, quarters and eighths. They recognise increasing and decreasing number sequences involving 2s, 3s, 5s and 10s, identify the missing element in a number sequence, and use digital technology to produce sequences by constant addition.
- Matching numbers and situations
- Representing 3-digit numbers with models
- Make this number
- ‘What is my number?’
- Learning from home
Matching numbers and situations
Students choose a 3-digit number or, using dice or spinners, generate a 3-digit number. They demonstrate what they know about this quality by writing it in digits, words, and in a story situation. They also can make a representation of this number and then, on their think board draw what they have made and be able to explain why.
Representing 3-digit numbers with models
Initially use proportional models with students to represent amounts. For example, ask students to ‘distribute’ 427 into 4 hundreds, 2 tens, 7 ones; and later: 427 ones; 42 tens, 7 ones. Also: 906 into 9 hundreds and 6 ones or 906 ones; and later: 90 tens and 6 ones.
Make this number
Students represent their number using as many ways as possible using proportional models such as MAB or bundles of pop-sticks etc. See image for example of how 1, 3 and 2 could be represented with MAB.
Students are encouraged to say and write the amounts they make: ‘one hundred and three tens and two ones is 132’.
Encourage students to read and say numbers as single quantities by ‘putting together the numbers in each place’, indicating further developing understanding and use of the conventions of the place value system.
‘What is my number?’
To promote discussion about the properties of numbers up to 1000 or 10 000, give students sticky labels and on them write a number. A child sticks a label on the back of another child who hasn’t seen the number. Using ‘yes’ and ‘no’ questions (one question per person), students move around the room to determine their number.
Alternatively assign the numbers to make deliberate choices such as numbers up to 1000 or 10,000 or whether to use decimal places.
Discuss the strategies used to identify numbers such as odd or even, higher than/less than and place value.
Learning from home
Children are ready to move to counting with numbers to 1000 (three digit numbers) once they are comfortable working with two digit numbers. This means counting beyond 100 and beyond the hundreds grids that they will have been working with prior to this point.
When moving to working with three digit numbers there are a couple of key ideas and concepts that are important for children to develop and these include:
- the digits in a number represent different 'place values'. ie. the '3' digit in the number 397 has a different value than the '3' digit in the number 237 because of the PLACE it occupies in the number.
- there are patterns that children can use to support them counting beyond 100 and these patterns are just an extension of the patterns that they learned to count up to 100.
Activities that you can do at home to support children to develop these concepts.
Supporting place value:
Have children count out a large number of items such as grains of rice or small coins like 5c coins. Nails or screws or washers also make good counting items. You need a few hundred of whichever items you choose.
Ask you child to group these items first into groups of ten, and then into tens of groups of tens (100s). Support your child to recognise that ten groups of ten items adds up to 100. Have them find more groups of 100 (ten groups of ten) until they cannot make them any more.
Support the child to then write what number of items they have by placing the correct digit in each place in the number. Use a template (draw three dashes on a piece of paper) to suggest that the child needs to identify the three digits. Ask them to count up how many groups of 10 (100s) they have. When they identify the correct number of groups, ask them to write that number in the correct place on the template. If they don't get it right or seem confused, ask them where do they think the number of 100s should go given that they already know where the number of tens should go and the number of ones.
Children may be uncertain about whether the 'ones' stay at the end of the number or if they move along a space. it is important to ensure that your child understands that the 'ones' stay at the end to the right and additional 'places' are added to the left.
Supporting pattern recognition:
Have your child watch the following short video clip that provides a song to support counting beyond 100. There are a number of these clips available through youtube that you might wish to search.