The idea in brief. Start from the largest place and move right until two digits differ; the first place that differs decides, and it decides by the VALUE of the digits there. Then read the question's own word: ascending means smallest first, descending means greatest first, and the list is written in that order and no other. The comparison starts at the largest place, and the question's own word, greatest first or smallest first, decides the order. In the lesson. Earlier, we saw that each digit gets its value from its place. Today, we compare numbers place by place, starting from the thousands, and put them in order. Start from the thousands, and the first place with different digits tells us which number is greater.
Lesson video, with the working
Comparing and ordering
4 min 34 s
The film teaches 3 questions in turn. Each question shows first; its working is written as the film explains it.
How do P3 children solve comparing and ordering numbers questions?
This page teaches children to compare and order numbers up to 10 000, the MOE Primary 3 outcome on comparing and ordering numbers.
What your child learns here
This page teaches children to compare and order numbers up to 10 000, the MOE Primary 3 outcome on comparing and ordering numbers. It rests on place value: two numbers are compared one place at a time.
Compare two 4-digit numbers by looking at the thousands first, then the hundreds, the tens and the ones.
Use the words greater, smaller, greatest and smallest correctly.
Arrange three or four numbers in ascending order (smallest first) or descending order (greatest first).
See that 10 000 is greater than every 4-digit number, and that any 4-digit number is greater than any 3-digit number.
Find a number that fits two comparisons at once, such as one that is greater than a given number and smaller than another.
Does the answer make sense?
In an ascending list each number must be smaller than the one after it, and a number with fewer digits, like 490, always comes before any 4-digit number. When the answer must sit between two given numbers, your child can test it against both: above the lower one and below the upper one.
How to practise these questions
The Basic questions train comparing two numbers by checking the thousands first, then each place to the right. The Intermediate questions add ordering a set of numbers from smallest to greatest or the reverse. In the Challenge questions, your child picks the correct list from several options or finds the number that fits a blank in a descending list, reasoning about which place decides. When comparing gets stuck, watch the solution film for that question, then come back to it later from Revision. The multiple-choice Basic questions ask which of four 4-digit numbers made from the same digits is the greatest; their solutions compare the places in writing and have no film.
Questions parents ask
What is the difference between ascending and descending order? Ascending order starts with the smallest number and ends with the greatest. Descending order is the reverse, greatest first. Reading that word in the question before writing the list keeps the order the right way round.
Which MOE outcome covers comparing numbers in P3? It is outcome 1.4, comparing and ordering numbers, in the Primary 3 topic Numbers up to 10 000. It comes straight after place value because comparing uses the value of each digit.
How can my child tell which number is greater without a number line? Compare the digits one place at a time, starting from the thousands. The first place where the digits differ decides, and the places to its right do not change the result. A number line still helps for numbers close together, so draw one if your child likes pictures.
