# NA2-4: Know how many ones, tens, and hundreds are in whole numbers to at least 1000.

This means students will develop an additive view of whole number place value by knowing the significance of the position of digits in a whole number, for example, in 456 the 5 means five tens. However, many strategies for computation require a nested view of place value. This means that nested in the hundreds are tens in the same way that nested in the hundreds and tens are ones, for example, 456 has 45 tens and 456 ones. An understanding of nested place value is best demonstrated by calculations where tens must be constructed from ones, hundreds constructed from tens, tens created from breaking hundreds and ones created from breaking tens. For example, calculations like 456 + 70 = , or 456 - = 396, show whether students can apply place value in this way.

know number of tens in numbers up to 100

use mental strategies to add numbers

**Session One**

- Calculate the gains and losses in a game of Snakes and Ladders.

**Session Two**

- Represent two digit numbers with play money.
- Add and subtract two digit numbers.

**Session Three**

- Use ‘up through ten’ and ‘back through ten strategies to add and subtract single digit numbers.

**Session**300

- Develop understanding of 3-digit numbers by composing and decomposing 100.
- Understand the structure of 3-digt numbers by modelling them using a range of material representations and contexts.
- Develop understanding of some benchmark numbers to 1000.
- Explore and understand the structure and size300

show understanding of ones, tens, hundreds place value

know how many tens are in whole numbers

use place value knowledge to add tens numbers

investigate "teen" and "ty" numbers

show understanding of place value using blocks and abacus

use place value knowledge to add

add and subtraction hundreds and tens numbers to 1000

- Develop an understanding of 1000 and the quantity for which it stands.
- Understand the relationship between 1000, 100 and 10.

- Students will be able to identify the impact on the value of a whole number when a zero is a place holder (for example 35 vs 305).
- Students will be able to accurately read numbers to at least 1000.

- Represent three digit whole numbers using numerals, words and materials (Place Value People Materials).
- Count in ones, tens and hundreds from a given three digit number.
- Find the difference between two three digit whole numbers.
- Use place value units of hundreds and tens to make estimates of300

**Session One**

- Represent four digit numbers using Place Value People and as compact and expanded numerals.

**Session Two**

- Apply place value to change a four digit number to a target number by addition or subtraction.

**Sessions Three and Four**

- Rename four digit numbers in flexible ways.

**Session**300

**Session One**

- Group a set of objects in tens to aid in counting the objects.

**Session Two**

- Recognise how many tens and ones are in a given collection.
- Read two-digit numbers used to represent quantities.

**Session Three**

- Partition (break up) 100 into two numbers using tens and ones place value300

- Use equipment to make numbers with hundreds, tens and ones.
- Representing numbers in place value houses.
- Understanding the importance of the place value of digits in numbers.

- Understanding place value of two- and three-digit numbers.
- Using place value to solve addition and subtraction problems.

- Understanding place value for numbers to four digits.
- Using equipment to explore place value.
- Using money to explore place value.
- Understanding the base ten nature of our number system.

- Understanding place value for numbers to four digits.
- Understanding algorithms for addition and subtraction.

round to the nearest ten or hundred

use the sign that means “approximately equals”

investigate "teen" and "ty" numbers

Show two-digit numbers using place value material.

show two-digit numbers using place value material.

Recall the number of tens and hundreds in 100s and 1000s.

Solve subtraction problems

solve subtraction problems

Recall the number of tens and hundreds in 100s and 1000s.