join (something) to something else so as to increase the size, number, or amount

I've started a petition so if you would like to add your name, email me

a new wing was added to the building

put in (an additional element, ingredient, etc.)

chlorine is added to the water to kill bacteria

when the mixture is soft, add the chopped tomatoes and simmer for another 10 minutes

put together (two or more numbers or amounts) to calculate their total value

in this example, all the odd numbers between 1 and 10 are added together

children learned to add and subtract quickly and accurately

say as a further remark

‘I hope we haven't been too much trouble,’ she added politely

we would like to add our congratulations

he added that few of the allies would support such an action