This add multiples of 10 and 100 worksheet has a set of problems curated to ensure that your child becomes more proficient in addition. Students use the count-on method or the relationship between addition and subtraction to find the missing number if it is an addend. Also, they add the addends to get the sum if the missing number is the sum. There is a lot of practice with this concept in the worksheet add multiples of 10 and 100. This worksheet is about practicing with the horizontal format in which numbers are written side by side. To develop flexibility with numbers and operations, students need to have enough practice in this format and not just rely on the vertical/column method.