How to Add

Step 4 Make groups

The previous few techniques have been delaing with adding two large-ish numbers. This one is more suited to "restaurant bill" type additions where you are adding a lot of very small numbers (or not very small, depending where you choose to eat).

This technique uses the fact that most people who have done maths for any length of time recognise most single-digit additions without even having to think about them- 2+2 is the obvious example but any maths student should be able to do 5+7 or 8+8 without too much thought.

When confronted by a string of numbers to add, you can simplify it by spotting groups that you can combine using the instinctive additions above. As a simple example, 2+2+3+4 could become 4+3+4 by pairing the twos, then 8+3 by pairing the 4s. If the numbers are out of order the pairs may be scattered, but in a longer example like the above you could even group all of the similar digits together and turn them into a multiplication, so you could start 2+5+7+2+7+3+8+2+4+6+2 by removing the four twos and adding an eight.

Pros: conceptually simple, general
Cons: requires holding a lot of working in your head, at risk of "losing count" and making mistakes.