Counting Numbers

Counting from 0 to 100Forward Counting and Backward CountingSkip Counting by 2s, 5s, and 10sCounting Objects and Using PicturesCounting in Real-Life Situations

Counting from 0 to 100

What is counting from 0 to 100?

Counting means saying numbers in order. When we count from 0 to 100, we say all the numbers starting at 0 and ending at 100. Zero (0) means nothing or empty. One hundred (100) means ten groups of ten.

  • Numbers help us know how many things we have
  • We use counting every day to find quantities
  • The numbers from 0 to 9 are called one-digit numbers
  • The numbers from 10 to 99 are called two-digit numbers
  • 100 is the first three-digit number

Number Families:

Family NameNumbersSpecial Feature
Ones0, 1, 2, 3, 4, 5, 6, 7, 8, 9One digit only
Teens10, 11, 12, 13, 14, 15, 16, 17, 18, 19Start with 1
Twenties20, 21, 22, 23, 24, 25, 26, 27, 28, 29Start with 2
Thirties to Nineties30 to 99First digit 3 to 9
Hundred100Three digits
Figure — Counting from 0 to 100
01234567891011121314151617181920 Number Line 0 to 20
1
Worked Example

Count from 0 to 10 out loud.

Solution
  • Start at 0
  • Say each next number: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
  • You have said 11 numbers total (0 through 10)

Answer: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

2
Worked Example

Look at the number chart. What number comes just after 49?

Solution
  • Find 49 on the number chart
  • The number after 49 is one more
  • 49 + 1 = 50
  • After 49 comes 50

Answer: 50

3
Worked Example

Sam has 0 cookies. His mom gives him 1 cookie every day for 5 days. How many cookies does Sam have on day 5?

Solution
  • Day 0 (start): 0 cookies
  • Day 1: 0 + 1 = 1 cookie
  • Day 2: 1 + 1 = 2 cookies
  • Day 3: 2 + 1 = 3 cookies
  • Day 4: 3 + 1 = 4 cookies
  • Day 5: 4 + 1 = 5 cookies
  • After 5 days, Sam has 5 cookies

Answer: 5 cookies

Key Points

  • Counting numbers start from 0 and go up to 100
  • 0 means "nothing" or "empty"
  • Numbers from 0 to 9 have one digit
  • Numbers from 10 to 99 have two digits
  • 100 is the first three-digit number
  • Each number is one more than the number before it

Forward Counting and Backward Counting

What is forward counting?

Forward counting means moving to bigger numbers. We say numbers in increasing order: 1, 2, 3, 4, 5... When we go forward, each next number is one more.

What is backward counting?

Backward counting means moving to smaller numbers. We say numbers in decreasing order: 10, 9, 8, 7, 6... When we go backward, each next number is one less.

When do we use forward and backward counting?

SituationType of CountingExample
Counting objectsForward1, 2, 3 apples
Countdown to an eventBackward5, 4, 3, 2, 1, Blast off!
Climbing stairsForwardStep 1, Step 2, Step 3
Going down stairsBackwardStep 10, Step 9, Step 8
Adding more itemsForwardHad 4, got 2 more = 5, 6
Taking away itemsBackwardHad 7, ate 3 = 6, 5, 4
Figure — Forward Counting and Backward Counting
1234567891011121314151617181920 Number Line 1 to 20
1
Worked Example

Count forward from 25 to 35.

Solution
  • Start at 25
  • Add 1 each time until reaching 35
  • 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35
  • Count the numbers: 11 numbers in total

Answer: 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35

2
Worked Example

Count backward from 42 to 35.

Solution
  • Start at 42
  • Subtract 1 each time until reaching 35
  • 42, 41, 40, 39, 38, 37, 36, 35
  • Check: 42 - 8 = 35

Answer: 42, 41, 40, 39, 38, 37, 36, 35

3
Worked Example

Riya has 15 stickers. She gives 3 stickers to her friend. Count backward to find how many stickers Riya has left.

Solution
  • Start with 15 stickers
  • Give away 1 sticker: 15, 14 (1 left to give)
  • Give away 2nd sticker: 14, 13 (2 left to give)
  • Give away 3rd sticker: 13, 12 (3 given, 0 left to give)
  • Riya now has 12 stickers
  • Backward counting sequence: 15, 14, 13, 12

Answer: 12 stickers

Key Points

  • Forward counting goes to bigger numbers (add 1 each time)
  • Backward counting goes to smaller numbers (subtract 1 each time)
  • Use forward counting when getting more items
  • Use backward counting when taking away items
  • Number lines help us see forward (right arrow) and backward (left arrow)
  • Countdowns (like for rockets) use backward counting

Skip Counting by 2s, 5s, and 10s

What is skip counting?

Skip counting means counting by numbers greater than 1. Instead of adding 1 each time, we add the same bigger number again and again. Skip counting helps us count things faster!

Skip counting by 2s: Add 2 each time → 2, 4, 6, 8, 10... (even numbers only)

Skip counting by 5s: Add 5 each time → 5, 10, 15, 20, 25... (ends with 0 or 5)

Skip counting by 10s: Add 10 each time → 10, 20, 30, 40, 50... (ends with 0)

Skip Counting Patterns:

Count byPatternLast Digit PatternReal-Life Use
2s2, 4, 6, 8, 10, 12...2,4,6,8,0 repeatsCounting shoes (pairs)
5s5, 10, 15, 20, 25, 30...5,0 repeatsCounting fingers
10s10, 20, 30, 40, 50, 60...0 onlyCounting dimes
Figure — Skip Counting by 2s, 5s, and 10s
Skip Counting By 2s: 2 4 6 8 10 12 +2 +2 +2 +2 +2 By 5s: 5 10 15 20 25 +5 +5 +5 +5 By 10s: 10 20 30 40 50 60 +10 +10 +10 +10 +10 Add the same number each time — that is skip counting!
1
Worked Example

Skip count by 2s from 2 to 20.

Solution
  • Start at 2
  • Add 2 each time: 2 + 2 = 4, 4 + 2 = 6, 6 + 2 = 8
  • Continue until you reach 20
  • All numbers will be even (2, 4, 6, 8, 10, 12, 14, 16, 18, 20)

Answer: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20

2
Worked Example

There are 4 hands. How many fingers in total? Use skip counting by 5s.

Solution
  • Each hand has 5 fingers
  • 1st hand: 5 fingers
  • 2nd hand: 5 + 5 = 10 fingers
  • 3rd hand: 10 + 5 = 15 fingers
  • 4th hand: 15 + 5 = 20 fingers
  • Skip counting sequence: 5, 10, 15, 20

Answer: 20 fingers

3
Worked Example

A toy car costs 10 rupees. Raj wants to buy 7 toy cars. How many rupees does he need? Use skip counting by 10s.

Solution
  • Each car costs 10 rupees
  • 1 car: 10 rupees
  • 2 cars: 10 + 10 = 20 rupees
  • 3 cars: 20 + 10 = 30 rupees
  • 4 cars: 30 + 10 = 40 rupees
  • 5 cars: 40 + 10 = 50 rupees
  • 6 cars: 50 + 10 = 60 rupees
  • 7 cars: 60 + 10 = 70 rupees
  • Skip counting sequence: 10, 20, 30, 40, 50, 60, 70

Answer: 70 rupees

Key Points

  • Skip counting means adding the same number each time
  • Count by 2s → all numbers are even (2, 4, 6, 8, 10...)
  • Count by 5s → numbers end with 0 or 5 (5, 10, 15, 20...)
  • Count by 10s → numbers end with 0 (10, 20, 30, 40...)
  • Skip counting helps count large groups faster
  • Use skip counting for pairs (2s), fingers (5s), and dimes (10s)

Counting Objects and Using Pictures

What is counting objects?

Counting objects means finding how many items are in a group. We touch or point to each object and say a number. The last number we say tells us the total.

How to count objects correctly:

  • Point to each object as you count
  • Say one number for each object
  • Do not skip any object
  • Do not count the same object twice
  • The last number you say is the answer

Counting using pictures:

Pictures help us count things we cannot touch. We can:

  • Put a mark on each picture as we count
  • Count in rows (left to right, top to bottom)
  • Group pictures to count faster
Counting MethodHow It WorksBest For
One-to-one countingTouch each itemSmall groups (1-20)
Skip countingCount by 2s, 5s, 10sLarge groups
GroupingMake groups of 5 or 10Very large groups
Picture markingDraw dots or linesWorksheets
Figure — Counting Objects and Using Pictures
Counting Objects 🍎🍎🍎 🍎🍎 ← 5 apples = 5 ⭐⭐⭐ ← 3 stars = 3 Tally Marks: = 5 items Always point to each object — count once, don't skip!
1
Worked Example

Count the number of stars: ★ ★ ★ ★ ★

Solution
  • Point to the first star: 1
  • Point to the second star: 2
  • Point to the third star: 3
  • Point to the fourth star: 4
  • Point to the fifth star: 5
  • The last number is 5

Answer: 5 stars

2
Worked Example

Count the total number of objects in this picture:

🐶 🐶 🐶 🐱 🐱 🐭

Solution
  • Count the dogs: 1, 2, 3 (3 dogs)
  • Count the cats: 4, 5 (2 cats)
  • Count the mouse: 6 (1 mouse)
  • Add them: 3 + 2 + 1 = 6
  • Final count: 1, 2, 3, 4, 5, 6

Answer: 6 animals

3
Worked Example

A picture shows 4 rows of flowers. Each row has 5 flowers. How many flowers in total? Use two different counting methods.

Solution
  • Method 1 (Count by 1s): Count each flower → 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20
  • Method 2 (Skip count by 5s):

- Row 1: 5 flowers

- Row 2: 5 + 5 = 10 flowers

- Row 3: 10 + 5 = 15 flowers

- Row 4: 15 + 5 = 20 flowers

  • Both methods give the same total

Answer: 20 flowers

Key Points

  • One number for each object when counting
  • The last number you say tells the total
  • Touch or point to each object as you count
  • Pictures can be counted like real objects
  • Tally marks (||||) help keep track while counting
  • You can count in rows from left to right, top to bottom

Counting in Real-Life Situations

Why do we need counting in real life?

We count things every single day! Counting helps us know how many of something we have, need, or want. It helps us share things fairly and plan our day.

Real-life counting examples:

  • At home: Counting plates, spoons, chairs, family members
  • At school: Counting students, books, pencils, days until vacation
  • At the store: Counting money, fruits, toys, candies
  • While playing: Counting players, points, steps, jumps
  • During cooking: Counting eggs, cups of flour, minutes on timer

Counting in daily routines:

Time of DayWhat We CountWhy It Matters
MorningHow many teeth brushed, shoes wornGetting ready
BreakfastHow many bites, glasses of milkHealthy eating
SchoolHow many classmates, books in bagOrganization
PlaytimeHow many friends, turns in gameFair play
BedtimeHow many stories read, stars outsideRoutine
Figure — Counting in Real-Life Situations
Counting Objects 🍎🍎🍎 🍎🍎 ← 5 apples = 5 ⭐⭐⭐ ← 3 stars = 3 Tally Marks: = 5 items Always point to each object — count once, don't skip!
1
Worked Example

Mom bought 2 apples, 3 bananas, and 4 oranges. How many fruits did she buy in total?

Solution
  • Count the apples: 1, 2 (2 apples)
  • Count the bananas: 3, 4, 5 (3 bananas - continue counting)
  • Count the oranges: 6, 7, 8, 9 (4 oranges - continue counting)
  • Total count: 1, 2, 3, 4, 5, 6, 7, 8, 9
  • Last number is 9

Answer: 9 fruits

2
Worked Example

There are 5 children playing. Each child has 2 hands. How many hands are there in total? Use real-life counting.

Solution
  • Think: Each child has 2 hands
  • Child 1: 2 hands
  • Child 2: 2 + 2 = 4 hands
  • Child 3: 4 + 2 = 6 hands
  • Child 4: 6 + 2 = 8 hands
  • Child 5: 8 + 2 = 10 hands
  • Skip counting by 2s: 2, 4, 6, 8, 10

Answer: 10 hands

3
Worked Example

Rohan is saving money. He has 3 coins of ₹5 and 2 coins of ₹10. How much money does Rohan have?

Solution
  • First, count the ₹5 coins by 5s: 5, 10, 15 (₹15 from ₹5 coins)
  • Next, count the ₹10 coins by 10s: 10, 20 (₹20 from ₹10 coins)
  • Add both amounts: ₹15 + ₹20 = ₹35
  • Verify by counting all coins in order: ₹5, ₹10, ₹15, ₹20, ₹25 (wait, that's wrong!)
  • Correct way: ₹5 (first ₹5 coin) → ₹10 (second ₹5 coin) → ₹15 (third ₹5 coin) → add ₹10 coin: ₹25 → add another ₹10 coin: ₹35
  • Total money is ₹35

Answer: ₹35

Key Points

  • We count every day in many situations
  • Counting helps us share things fairly
  • Use different counting methods (1s, 2s, 5s, 10s) for different real-life things
  • Money is a great way to practice skip counting
  • Games use counting for scores and turns
  • Always double-check your count in real life to avoid mistakes