# Place Value

## Decimals

It is important when pronouncing numbers that include a decimal that students are showing an understanding of the value of each digit following the decimal point. At Forest Street Primary, when teaching and learning about decimals, we follow the pattern set out below: Decimal Point 5 tenths (not “point 5”) 59 hundredths (not “point 59”) 591 thousandths (not “point 591”)

## Renaming

Renaming is writing a number in an equivalent form, usually in terms of its place-value parts. For example: 462 is 4 hundreds 6 tens and 2 ones, but it can be renamed as 46 tens and 2 ones, or 4 hundreds and 62 ones 4.35 = 4 ones, 3 tenths, 5 hundredths = 43 tenths, 5 hundredths = 435 hundredths

## Base 10

Base ten blocks, also known as multibase arithmetic blocks (MAB) or Dienes blocks (after their creator, mathematician and educationalist Zoltán Pál Dienes), are a mathematical manipulative used by students to learn basic mathematical concepts including addition, subtraction, number sense, place value and counting. At Forest Street, the language we use is “base 10” as it relates to the place value

## Zero

The numeral 0 that has the value of nothing, none, nil or nought.

## Unifix

Unifix cubes are colourful interlocking cubes that help mathematicians learn number and math concepts.

## Ty Numbers

The multiples of ten up to 90 (20, 30, 40) are often called the ty numbers. Some children confuse them with the teen numbers (13, 14, 15…).

## Ten Frame

A setting consisting of a 2×5 rectangular array which is used to support children’s thinking about combinations to 10 (for example, 7+3) and combinations involving 5 (for example, 7 is 5+2).

## Teen Numbers

The numbers from 13 to 19 are often referred to as teen numbers. Some children confuse them with the -ty numbers (20, 30, 40).

## Partitioning

An arithmetical strategy involving partitioning a small number into two parts without counting, typically with both parts in the range 1 to 5, for example partitioning 6 into 5 +1, 4+2 and so on.

## Part-Whole Thinking

The ability to conceive simultaneously of a whole and two parts, e.g. conceiving of 10 and also of the parts 6 and 4. This means the mathematicians do not need to rely on counting-by-ones to add and subtract.