These addition grids enable children to understand the commutativity of addition as they find the sum of numbers at the top of each column and start of each row.

Numbers throughout this worksheet have been carefully selected to build students' confidence in mentally adding to three digit numbers.

The first line of questions sees students adding multiples of tens to multiples of 100 and progresses to adding multiples of 10 to any three digit number.

There are 36 questions to answer in total. Some regrouping is required.