Working with Decimals

Scheme of work: GCSE Foundation: Year 9: Term 5: Working with Decimals

Read and write decimal numbers as fractions [for example, 0.71 = 71/100 ]
recognise and use thousandths and relate them to tenths, hundredths and decimal equivalents
round decimals with two decimal places to the nearest whole number and to one decimal place
read, write, order and compare numbers with up to three decimal places

Order positive and negative decimals
use the symbols =, +, – x and /
apply the four operations, including formal written methods, to integers, decimals and simple fractions (proper and improper), and mixed numbers â€“ all both positive and negative;
understand and use place value
recognise and use relationships between operations
estimate answers; check calculations using approximation and estimation, including answers obtained using technology

Use the place value table to teach the column method of addition and subtraction of decimal numbers. This helps students to align the digits to the decimal place.
When calculating with decimal numbers encourage students to estimate the solution as means to check their working.
Students may need to recap multiplying and diving by powers of ten when calculating the product of decimal numbers.
Use equivalent fractions when performing long division. Simplifying the fractions help to break down the calculation.

Students incorrectly consider multiplications to always increase a number and divisions to decrease.
Students fail to spot incorrect calculations due to not estimating solutions.