Counting and comparing quantities helps young students understand what numbers mean. This cheat sheet gives simple rules for counting objects, reading numbers to 20, and deciding which group has more or fewer. Students can use it as a quick reference during classwork, math centers, or homework.
Clear examples help children connect number words, written numbers, and groups of objects.
The most important ideas are counting each object one time, keeping numbers in order, and knowing that the last number counted tells how many there are. Students also learn to compare two groups using more, fewer, the same, greater than, less than, and equal to. Symbols such as >, <, and = can show comparisons after students understand the groups.
Careful counting and matching make comparing easier and more accurate.
Key Facts
- Counting numbers from 1 to 20 goes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.
- When counting objects, touch or point to each object one time and say one number for each object.
- The last number you say when counting a group tells how many objects are in the group.
- If one group has more objects than another group, its number is greater, such as 8 is greater than 5.
- If one group has fewer objects than another group, its number is less, such as 4 is less than 7.
- If two groups have the same number of objects, they are equal, such as 6 = 6.
- The greater than symbol > points from the bigger number to the smaller number, such as 9 > 3.
- The less than symbol < points from the smaller number to the bigger number, such as 2 < 10.
Vocabulary
- Count
- To count means to say numbers in order to find how many objects there are.
- Quantity
- A quantity is the number of objects in a group.
- More
- More means a group has a larger number of objects than another group.
- Fewer
- Fewer means a group has a smaller number of objects than another group.
- Equal
- Equal means two groups or numbers are the same amount.
- Compare
- To compare means to look at two groups or numbers and decide which is more, fewer, or the same.
Common Mistakes to Avoid
- Skipping an object while counting is wrong because the final number will be too small.
- Counting the same object twice is wrong because the final number will be too large.
- Saying numbers out of order is wrong because counting depends on the correct number sequence.
- Choosing the group that looks bigger without counting can be wrong because spread-out objects may look like more.
- Mixing up > and < is wrong because the open side should face the greater number, such as 12 > 8.
Practice Questions
- 1 Count these objects: 5 red cubes and 3 blue cubes. How many cubes are there in all?
- 2 Which number is greater: 14 or 9?
- 3 Write the missing numbers: 11, 12, __, 14, __, 16.
- 4 Two groups of buttons look different because one group is spread out and one group is close together. How can you find out if the groups are equal?