# Number – Sequencing and Ordering four digit numbers

SequencingAnumber sequenceis a list ofnumbersthat are linked by a rule. If you work out the rule, you can work out the nextnumbersin thesequence.Number sequenceis a progression or an ordered list ofnumbersgoverned by a pattern or rule.Numbersin asequenceare called terms. Asequencethat continues indefinitely without terminating is referred to as infinitesequence, whereas asequencewith an end is known as finitesequence. Below are different types of number sequencesOrdering NumbersOrdering numbersmean arrangement ofnumberseither from small to big or from big to small. When we arrange thenumbersin anincreasingorder, it is known asAscendingOrder, and when the words are arranged in adecreasingorder, and then they are known asDescendingOrder.Using the comparison techniques learnt in the previous lessons is the key step to knowing how to order numbers.Ascending Order (small to big)Take the following numbers for example: 4567, 1398,1278,1238 Let's first look at the thousands place for each number listed.4567139812781238 By comparison of the thousands place we know that one(1) is the smallest number but three of those numbers begin with one. So the next step is to look at the hundreds place: 1398, 1278, 1238 By comparison we can see that two(2) is the smaller number but again two numbers have two(2) in the hundreds place. Therefore the next step to finding the smallest number is to compare the tens place. 1278, 1238 Looking at both numbers we can clearly see that three(3) is smaller than seven(7) so we can say that 1238 is the smaller number between the two. Now we can put the numbers in Ascending order(smallest to largest). The list of numbers were 4567, 1398, 1278,1238 and following the steps we just did we know that the order they should be sorted in is 1238 1278 1398 4567Descending Order (Big to Small)Take the following numbers for example: 4567, 1398,1278,1238 Let's first look at the thousands place for each number listed.4567139812781238 By comparison of the thousands place we know that four(4) is the largest number, therefore it would the first number listed. Let's now look at the other three numbers 1398,1278,1238. We can clearly see that all three numbers begin with one (1) hence the next step is to look at the hundreds place. 1398 1278 1238 Three(3) is the smaller number so we know that the next number in the order sequence is 1398. Let's look at the remaining two numbers 1278, 1238 they both have one(1) in the thousands place and two(2) in the hundred place. So we have to look at the tens place: 1278 1238 The larger of the two numbers is seven(7) so we know that the next number in the sequence is 1278. Which means the last number in the sequence should be 1238. The original list is4567139812781238 and the list sorted in descending order is 4567, 1398, 1278 and 1238.