Transcript Subtraction - Martin Frobisher Infant School

Mathematics at Martin
Frobisher Infant School
Subtraction
Subtraction
National curriculum- End of year 2
expectations linked to subtractions
Expected

Pupils can subtract mentally two 2-digit numbers
mentally where there is no regrouping required
(e.g. 74 – 33)

The pupil can recognise the inverse relationship
between addition and subtraction and use this to
check calculations and work out missing number
problems.
Resources we use in school
 Numicon Base
year one
10
 Diennes
apparatus
 Number
track
 Number
line
 Brain
only!
Building blocks in subtraction
Early subtraction in year one

Starting with number bonds- we know that 6 + 4 =
10 so 10 – 4 = 6 and 10 – 6 = 4

Subtract 1 digit from 1 digit using apparatus
(Numicon)

Use of pictures and marks
Moving on to more formal methods
Number lines

Starting in year one- counting back or down the number
line

Make sure children record jumps underneath the number
line

Moving on to counting on or up the number line to find the
‘difference between’ (helpful for children who are more
confident with addition)

Encouraging children to record their jumps, then move on
to constructing their own number lines.
Number lines- how it develops into year 2

We continue using number line methods in year 2

Find small differences by counting up (e.g. 42 –
39)

Understand how we can use multiples of ten for
1/9 digits (e.g. 35 – 9)

Partitioning the second number to subtract (e.g.
37 – 12 = 37 – 10 – 2)
Fluency – Reasoning – Problem Solving

Once children have understanding of the method
and can subtract fluently, they can move on to
reasoning and problem solving challenges.

Maths is not just about the fluency.
Questions
 Any
questions?
Opportunity to work with child