Counting In Tens

Counting in tens means saying numbers by adding or taking away 10 each time. When we count in tens we get this pattern: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100. Notice the ones digit is always 0 and only the tens place (1, 2, 3, ...) changes.

Why it helps: grouping objects in tens makes counting faster. Instead of counting 1 by 1, we group items into sets of ten and count the sets.

How to read numbers in tens using place value: 10 = 1 ten + 0 ones, 50 = 5 tens + 0 ones, 100 = 10 tens + 0 ones. We can also use multiplication: the nth ten is 10 × n (for example, the 7th ten is 10 × 7 = 70).

Ways to practice: make groups of ten objects (pencils, beads), jump on a number line in steps of ten, or color every tenth square on a hundred chart. You can count forwards (10 → 20 → 30 ...) and backwards (100 → 90 → 80 ...).

What it means: Counting in tens means moving from one number to the next by adding or subtracting 10 each time. We usually count the multiples of 10: 0, 10, 20, 30, ... or go backwards: 100, 90, 80, ...

Why it works (place value): Each move of 10 changes the tens place by 1 while the ones place stays 0. For example, when you go from 40 to 50 the tens digit goes from 4 to 5 and the ones digit stays 0.

How to do it — forward: Start at a number that is a multiple of 10 (for example 20). To count forward in tens, keep adding 10: 20 → 30 → 40 → 50. Use a number line or finger jumps to show equal steps.

How to do it — backward: Start at a multiple of 10 (for example 80). To count backward in tens, keep subtracting 10: 80 → 70 → 60 → 50. Show this on a number line with jumps going left.

Tips for children:

• Use a hundred chart and colour the tens column (10, 20, 30, ...).
• Use groups of 10 objects (bundles) so students see 10 as one group and count groups.
• On a number line, draw equal jumps labelled +10 or −10 to practise forward and backward steps.

Common activities: Fill in missing tens in a sequence, count forward/backward from any multiple of 10, and clap or hop for each +10 or −10 step.

What it means: Grouping objects in tens means making small bundles where each bundle has 10 items. It helps us count many things quickly and shows the place value idea of tens and ones.

Why we do it: When we make groups of 10, we can count by tens (10, 20, 30, ...) instead of counting one by one. This makes counting faster and helps children understand that numbers have tens and ones.

How to group (step-by-step):

• Gather the objects (pencils, beads, counters, etc.).
• Put 10 objects together to make one bundle (use a rubber band, a tray section, or a box space).
• Make as many full bundles of 10 as you can.
• Count how many bundles of 10 you have (this gives the number of tens).
• Count any remaining single objects (these are the ones).
• Write the total as: (number of tens) tens and (number of ones) ones. Example: 3 tens and 4 ones = 34.

Example explained: If you have 34 pencils, make 3 bundles of 10 pencils (that is 30) and 4 single pencils left. So 34 = 3 tens and 4 ones.

Counting tip: After grouping, use skip counting by tens: 10, 20, 30, ... and then add the leftover ones to get the total.

Classroom activities: Use ten-frames, strips of 10 counters, place-value charts labeled Tens and Ones, or an abacus with groups of 10 to practise.

What is place value? Place value tells us the value of each digit in a number depending on its position. For two-digit numbers we use two places: Tens and Ones.

Tens and Ones explained

• The rightmost digit is the Ones place. It shows how many single units there are.
• The digit to the left of the Ones is the Tens place. Each ten is equal to 10 ones.

How to read and make a two-digit number

• To read a number, say the tens part first and then the ones. For example, 34 is read as 3 tens and 4 ones which is spoken as thirty-four.
• To make a number from tens and ones, multiply the tens digit by 10 and add the ones. Example: 3 tens and 4 ones = 3 × 10 + 4 = 34.

Decomposing numbers

Every number from 10 to 99 can be split into tens and ones. Examples:

• 57 = 5 tens + 7 ones = 5 × 10 + 7
• 20 = 2 tens + 0 ones = 2 × 10 + 0
• 9 = 0 tens + 9 ones = 0 × 10 + 9

Teaching tip for Class 2: Use real objects (pencils, erasers, coins) and group them in bundles of ten. Show that ten single items tied together become one bundle (one ten). Count bundles as tens and loose items as ones.

What are tens? Tens are numbers made of whole groups of ten. They end with the digit 0: 10, 20, 30, ..., 90, 100. Each of these numbers is a certain number of tens: 10 = 1 ten, 20 = 2 tens, and so on.

Numerals and number names
Every ten has a numeral (the digit form) and a number name (the word). For example, the numeral 40 is written as 40 and its number name is forty. The standard names from 10 to 100 are: 10 ten, 20 twenty, 30 thirty, 40 forty, 50 fifty, 60 sixty, 70 seventy, 80 eighty, 90 ninety, 100 one hundred.

How to read and write tens
- To write a number for n tens: multiply n by 10. Example: 3 tens = 3 × 10 = 30. The numeral is 30 and the name is thirty.
- To find how many tens a numeral represents: divide the number by 10 (only if the last digit is 0). Example: 80 ÷ 10 = 8, so 80 is 8 tens.

Pattern and rules
- Tens always end with 0 in numeral form.
- Most names for tens are formed by the base word for the digit plus -ty (two → twenty, four → forty), with some irregular spellings (three → thirty, five → fifty, eight → eighty).
- Tens help us skip-count: 10, 20, 30, 40, ... — useful for quick counting and grouping objects.

Teaching tip
Use physical groups of ten (bundles of 10 sticks, groups of 10 counters) so children see that each bundle equals one ten. Show how several bundles make larger tens numbers (for example, 4 bundles = 40).

What it means: Patterns and sequences with tens are number patterns where each number increases or decreases by 10. These are also called multiples of 10. Examples: 10, 20, 30, 40... (forward) and 100, 90, 80, 70... (backward).

How to recognise the pattern: Every number ends with a zero. To move forward one step, add 10. To move backward one step, subtract 10. You can skip-count by tens: 10, 20, 30... or count backwards by tens: 100, 90, 80...

Why it helps: Grouping things in tens makes counting faster (for example, bundles of pencils, egg trays, or money notes). It also builds a foundation for place value and later addition and subtraction strategies.

Simple rules you can use:

• Add 10 to get the next number.
• Subtract 10 to get the previous number.
• Look for the last digit 0 to spot multiples of 10.

Activities for learners: Give a number and ask for the next three numbers by adding 10 each time. Give a sequence with a missing number (e.g. 20, __, 40) and ask the child to fill it. Group 10 objects together and count how many tens there are.

What are multiples of ten? Multiples of ten are numbers you get when you multiply 10 by a whole number: 10, 20, 30, 40, ... Every multiple of ten ends with the digit 0.

How to compare multiples of ten

• Look at the number of tens (the digit(s) before the final 0). For example, 70 has 7 tens and 30 has 3 tens.
• Whichever has more tens is the greater number: 70 > 30 because 7 tens > 3 tens.
• If they have the same number of tens, they are equal (e.g., 50 and 50).
• Use the symbols > (greater than), < (less than), and = (equal to) when writing comparisons.

How to order multiples of ten

• To arrange from smallest to largest (ascending): put the numbers in order of increasing tens (e.g., 10, 20, 30...).
• To arrange from largest to smallest (descending): put the numbers in order of decreasing tens (e.g., 100, 90, 80...).
• Using a number line or place-value blocks helps children see and order the numbers easily.

Tips for teaching and learning

• Count in tens aloud: 10, 20, 30, ... to build the pattern.
• Use ten-blocks or groups of 10 objects so students can physically compare groups.
• Draw a number line with marks at multiples of ten to show distance between numbers.

What it means: "Counting in Tens" means counting objects by making groups of ten and then adding those groups. This helps children skip-count by 10s (10, 20, 30...) and understand place value: 1 ten = 10 ones, 2 tens = 20 ones, etc.

Why it is useful: Grouping in tens makes counting large amounts faster, helps with addition and subtraction of multiples of 10, and introduces the idea of multiplication (repeated addition) in a simple way.

Activities:

• Make groups of 10 objects (pencils, pebbles, beads). Count how many full groups and how many extra ones remain.
• Use a number line and take big jumps of 10 to show skip counting: start at 0, jump to 10, 20, 30...
• Use a tens frame (a 2×5 box) or a 10-stick (bundle of 10 straws) and show how each bundle equals 10.
• Create a pictograph: draw one symbol for every 10 apples to show quick totals.

Exercises and strategies:

1. Fill in the missing numbers in sequences that skip by 10: 10, __, 30, __, 50.
2. Add and subtract tens using grouping: 40 + 30 = (4 tens + 3 tens) = 7 tens = 70.
3. Turn word problems into groups: If there are 4 boxes with 10 toy cars each, write 10 + 10 + 10 + 10 or 4 × 10 and count the total.
4. Use place-value thinking: write the number as tens and ones (e.g., 34 = 3 tens and 4 ones). To add 20, add 2 tens to the tens column.

Solving word problems — simple steps: Read the problem. Find what is grouped by 10. Count how many groups. Add the groups (use repeated addition or count by tens). Write the final number and answer in a sentence.

Tips for teachers/parents: Use real objects and visuals. Encourage children to verbalize "one ten, two tens..." while counting. Celebrate correct grouping to build confidence.