Complete the following pattern: nine, eight, seven, what, and what?
We’re given a pattern which contains five numbers. The first three numbers are given: nine, eight, seven. We have to find the next two numbers. Before we can find the two missing numbers, we need to work out the rule of the pattern. In other words, what is happening to the numbers each time? How do we get from number nine to number eight?
We need to count back one on the number line. Eight is one less than nine. Which number is one less than eight? If we start at eight and count back one, we land on number seven. Now we can find the first missing number. This number is one less than seven. One less than seven is six. Our second missing number is one less than number six, which is number five.
We had to complete the pattern nine, eight, seven, followed by two missing numbers. We realized the rule of the pattern was to count back in ones: nine, eight, seven, six, five. The two missing numbers are six and five.