In year 3 children will continue to develop their understanding of addition, moving on to  work  with larger numbers, up to three digits. The words below should be understood and written correctly. more    add    sum   total    altogether    equals    sign Most of this work can be done orally, with increasing speed of recall. Once the addition of single digits is secure, this knowledge can be applied to two digit and three digit problems with confidence. All kinds of opportunities arise where simple addition questions can be posed but the numbers do need to be kept simple. Mental work will concentrate on smaller numbers, usually tens and units or whole hundreds. Rapid recall is expected for answers up to 20. 'Rapid' means almost instant, where the child knows the answer rather than having to work it out. A number line from 0 to 100 is still a useful resource. It is also important to discuss how the sum has been done. Very often, when working mentally, it is easier to start with the tens and then add the units - the opposite to the usual pencil and paper method. Again it is important to talk about how children add in their heads. Ask questions all the time such as: "How did you work that out?" "What did you start with?" "Can you explain what you did?     etc. In year 3 children should be encouraged to use a variety of strategies when adding, including: Looking for pairs of numbers that make 10. Looking for pairs of numbers that make 9 or 11. Starting with the larger number and counting on, whichever way the sum is written or asked. Use knowledge of doubles such as 6 + 6. Use knowledge of doubles to find near doubles and then add or subtract 1. When finding the difference between two numbers which are quite close to each other eg 198 and 202 it is often easiest to start with the lower number and count on, rather than to start with the higher number and count back. Subtraction problems can often be made into 'counting on', or addition! Children continue to be expected to work out more complex addition in their heads. Adding 9  is extended to any three digit number. Adding 19, 29, 39 etc to any two digit number without crossing the hundred boundary is the next step e.g. 37 + 29. Because it is usually easier to add whole tens or a single digit the most effective method involves several steps: 1. adjusting a number to the nearest whole ten: e.g. 39 to 40 2. adding the 40 3. readjusting by subtracting 1. In year 3 addition of a single digit is extended to hundreds, for example 345 + 4, but the tens boundary is not crossed. Further developments include adding a two digit number to any multiple of 100, such as 500 + 34 and adding a two digit number to a multiple of ten where crossing the hundred boundary does occur e.g. 60 + 55. The second of these is much harder and children need to be secure in their knowledge of adding a pair of multiples of ten that cross the hundreds boundary e.g. 50 + 70 before they move on to this. In year three progressively more difficult mental addition continues, including: 1.    adding 10 to any two digit number with answers going up to and beyond the  hundreds 2. adding a pair of multiples of 10, beyond the hundreds e.g. 80 + 50 3. finding pairs of multiples of 10 that make the next multiple of 100  e.g. 230 and 70 4. add a multiple of 10 to any two digit number, crossing 100 e.g. 46 + 70 5. add a pair of multiples of 100, with answers crossing 1 000 6. add 100 to any three digit number, not crossing 1 000 All these are extensions of the work covered in year two. If children find them difficult it is strongly recommended that the year two work is re-enforced. Written methods Pencil and paper methods of addition are encouraged in year 3. To begin with ‘jottings’ can be used to help with the mental methods that children are already familiar with, leading to a more efficient method later. Hopping along a number line is a useful way to introduce these ‘jottings’. Go to Year 3 addition concepts