Year 5 Term 2

Key Concepts – Number – Addition and Subtraction

• That addition follows the commutative law (can be done in any order) but subtraction doesn’t.
• That the inverse of addition is subtraction and vice versa and that we can use this to help check our answers.
• That when we add positive numbers the sum is always greater than any of the individual numbers.
• Presentation is key to success in column addition and subtraction as it reflects place value.
• That when you add one digit numbers together and they total a number greater than 10, you must exchange this into a ten and put it into the tens column. The same should happen if you have more than 10 tens or more than 10 hundreds.
• Children should be able to look at a problem and decide on an appropriate and efficient method of calculation, eg not using columns subtraction for 100,000 – 1.
• Children should be able to select the appropriate operations from the vocabulary present in the questions and can explain the choices they have made.
• Estimation can be used to quickly check whether an answer is likely to be correct.
• Rounding can be used to generate an estimate to assist in checking the calculation.
• Children can accurately partition and exchange numbers in subtractions
• Children can articulate and explain their reasons and actions for completing the operations.

Key Vocabulary – Addition and subtraction

Total

Equal to

Sum

Ones, tens, hundreds and thousands, then thousands, hundred thousands

Difference between

Subtract

Take away

Add

Addition

Plus

Make

How many more

How many less

Inverse

Total

Increase

Commutative

Key Concepts – Perimeter

• That perimeter is used with 2D shapes
• That perimeter can be calculated by adding the length off all of the sides of a shape together.
• That perimeter allows you to calculate the total distance around the edge of a shape. Circumference is the name for perimeter used for circular shapes.
• That children understand the value of mm, cm and m and how to convert between these measurements
• Not all diagrams are drawn to scale and as such rulers cannot always be used.
• The length of a missing side can be calculated with knowledge of the opposite side(s)

Key Vocabulary

Length

Width

Perimeter   (Perimeter - ….meter not metre here!)

Measure

Scale

Estimate

Centimetre

Millimetre   ( Often spelt incorrectly ie meter not metre)

Metre

Common Misconceptions – Addition and Subtraction

That columns addition and subtraction are not always the best method to use and each question needs to be solved in the most efficient possible method.

That you are unable to subtract a larger positive number from a smaller positive number and get a positive number. (Often seen when using column subtraction)

Estimation and rounding can be used to check whether an answer is likely to be correct.

Children do not present their work accurately leading to issues with place value and nonsensical answers.

Common Misconception – Perimeter

That children will confuse area and perimeter.

When a shape has a missing measurement the children will just ignore the side.

Finding the perimeter of a 5 sided shape requires adding 5 numbers and so on.

Children do not always understand/realise that shapes on worksheets depict different values to the actual size of the shape, this needs to be a clear teaching point.

Children will use rulers in questions which are not drawn to scale leading to anomalous answers.

Children will not ensure that all measurements are in the same unit or incorrectly convert them.