Fill in the blanks in the figure below from left to right.
We can use a number line to help us answer this question. We need to start counting at number one. And we need to add seven or count forward seven places on the number line: one, two, three, four, five, six, seven, which takes us to number eight on the number line. So number eight is the first missing number, and we can fill in the blank.
Next, we have to start at number eight and subtract or take away five. That means we need to count backward five places on the number line: one, two, three, four, five. That takes us to number three on the number line, so we can fill in the blank.
Next, we have to start at number three and add five or count forward five places on the number line. When we were on number eight, we had to count back five places. If we reverse the direction in which we count and count forward five places, it will take us back to number eight. The missing numbers were eight, three, and eight.