Planning tool

Students:

• understand the importance of grouping in tens and hundreds and use this to describe their thinking
• flexibly rename numbers using the place value parts of hundreds, tens and ones, for example, can rename 245 as 24 tens and 5 ones, as well as 2 hundreds and 45 ones
• flexibly rename numbers that have internal zeros, for example, read 807 as ‘eight hundred and seven’ and can rename it as 80 tens and 7 ones
• order and rename three-digit numbers without materials (e.g. 247 is 2 hundreds, 4 tens and 7 ones, or 2 hundreds and 47 ones, or 24 tens and 7 ones)
• explain the role of zero.

Some students may:

• be able to count a collection (e.g. 36) and record the total but they may not understand the significance of the digits, that is, that the 3 represents 3 tens and the 6 represents 6 ones.
• be able to identify place-value parts (e.g. they can say that there are 4 hundreds, 6 tens and 8 ones in 468) but still think about two- or three-digit collections additively in terms of ones (understand 468 as the sum of 400 ones, 60 ones and 8 ones).

To address these, focus on grouping tens and build the foundational understanding required – that 10 ones is 1 ten, and 1 ten is 10 ones. Provide repeated opportunities to apply and develop this understanding with two-digit numbers up to 99 before working with three-digit numbers.

Some students may:

• have trouble naming, writing or modelling three-digit numbers that involve teens (e.g. 213, 319) or zeros (e.g. 207, 405). To address this, provide repeated opportunities to make, name, rename and write these kinds of numbers using concrete materials and tools such as place value charts.

Address misunderstandings students may have with this topic.

Common misunderstandings: Level 2 – Place value

The Learning from home activities are designed to be used flexibly by teachers, parents and carers, as well as the students themselves. They can be used in a number of ways including to consolidate and extend learning done at school or for home schooling.

Learning intention

• We are learning to understand and use numbers up to 999. 

Why are we learning about this?

• We use numbers and counting in everyday life.

What to do

Use two- and three-digit numbers every day. Here are some ideas:

1. Use numbers when measuring, such as making a recipe that involves using millilitres or litres, and grams or kilograms.
2. Play ‘General number knowledge’.
   • Choose a two-digit number and take turns at sharing what you know about it.
   • Person 1: chooses 35 and says ‘I know that 35 is how many years old Dad is’.
   • Person 2: ‘I know that 35 is too many days for a month’.
   • Person 1: ‘I know that 35 is 3 tens and 5 ones’.
   • Person 2: ‘I know 35 is 5 less than 40’.
   • Once you run out of ideas, it’s Person 2’s turn to choose a number.
3. When tidying up at home, notice ‘how many’ are in a collection. Organise objects so they’re easier to count.
4. Play board games such as Snakes and Ladders that involve two- or three-digit numbers.
5. Play 'Guess my number' or similar games. How to play:
   • Player 1 writes a secret three-digit number on a piece of paper.
   • Player 2 asks yes/no questions about it until they guess it. For example, you could ask questions like:
     • Is it larger than 500?
     • Does it have an odd number in the hundreds place?
   • Player 1 then provides an answer.
   • Use the answers to work out which numbers it could not be and those numbers that it could be.
   • Try and use questions that will reduce the number of possible numbers each time.

Success criteria

I can:

• explain how two-digit numbers (10–99) are made up of tens and ones
• explain how three-digit numbers (100–999) are made up of hundreds, tens and ones
• describe two- and three-digit numbers in different ways.