Addition up to 10

Addition up to 10 covers sums that stay within 10, working through sums to 5, then sums to 10, then adding 0. Alongside Calculation, children practice Fill in the Blank items that ask for the missing number in a box, Word Problems (with Pictures) where the equation is built from a picture, and Word Problems given in words only.

A common slip is writing 3 + 0 as 0, on the assumption that adding 0 makes the answer 0. In Word Problems (with Pictures), children count only one side of the picture and stop there. If the answer matches the larger of the two numbers, the joining situation has not been understood.

Elementary school mathematics opens with this unit. Counting on fingers or working through a picture one item at a time gives way to the operation of combining two numbers and counting the result. The way of counting introduced here carries straight over into Subtraction up to 10.