Count 21 to 99

NCERT anchor: NCERT Joyful Mathematics Class 1 — Chapter 8: Numbers from Twenty-one to Fifty and Chapter 13: How Many Times? (extended counting to 99)

• Count forward from 21 all the way to 99.
• Read and write two-digit numbers correctly.
• Find the number just before, just after, and between two numbers up to 99.

1. Counting past 20

After 20 comes 21, 22, 23… The pattern repeats: after every "X9" comes a new tens number (29 → 30, 49 → 50).

2. Just before and just after

The number just after 45 is 46. The number just before 45 is 44. Just after means "+1," just before means "−1."

3. Numbers between two numbers

The number between 56 and 58 is 57 — it sits exactly in the middle when numbers are counted one by one.

4. Counting by tens

10, 20, 30, 40… counting by tens skips the ones and jumps by a whole bundle of ten each time.

Counting seats in the school hall

Step 1 — The chairs are numbered starting from 21.
Step 2 — Point to each chair and say the next number: 21, 22, 23…
Step 3 — After 29, the next chair is numbered 30, not 210.
Step 4 — Continue counting up to the last chair, say 76.
Answer: The last chair in the row is numbered 76.

• What number comes just after 58?
• What number comes just before 70?
• What number is between 82 and 84?
• Stretch: Start counting by tens from 10. What is the 5th number you say?

Revision tip: Practise counting aloud from 21 to 99 every day, pointing to a 1–100 number chart.

Open the Practice tab for graded questions on Count 21 to 99.