Learn how every number is made of tens and ones — the first big idea in place value!
Numbers are not just symbols — they tell us how many of something we have. In this lesson you will learn that every 2-digit number is built from tens and ones. Once you know this, counting and adding big numbers becomes much easier!
Imagine you have a bag of apples. Instead of counting every single apple one by one, you put them into groups of 10. Each full group is one ten. Any leftover apples are ones.
For example, 34 apples = 3 groups of ten + 4 leftover ones.
In a number, every digit has a place. The place tells you how much that digit is worth. The digit on the right is in the ones place. The digit to its left is in the tens place.
So in the number 34, the 3 is not just worth 3 — it is worth 30, because it sits in the tens place!
Same digit, different place = different value. The digit 3 in 34 is worth 30. The digit 3 in 43 is worth only 3.
Let's look at the number 47 in a place value table:
| Tens | Ones |
|---|---|
| 4 | 7 |
The 4 is in the tens place — it is worth 40.
The 7 is in the ones place — it is worth 7.
So 47 = 40 + 7.
| Digit | Place Name | Value |
|---|---|---|
| 2 | Tens place | 20 |
| 5 | Ones place | 5 |
25 = 20 + 5 ✅
| Digit | Place Name | Value |
|---|---|---|
| 6 | Tens place | 60 |
| 3 | Ones place | 3 |
63 = 60 + 3 ✅
1. The right digit is always in the ones place.
2. The left digit (in a 2-digit number) is always in the tens place — multiply it by 10 to find its value.
3. 10 ones make 1 ten. You can always swap between them!
Mistake 1 — Mixing up left and right. Students sometimes think the left digit is the ones place. Remember: ones are always on the RIGHT side of the number.
Mistake 2 — Forgetting to multiply by 10. The digit 5 in the tens place is worth 50, not 5. Always ask: "Which place is this digit in?"
Mistake 3 — Reading digits individually. The number 47 is "forty-seven" — not "four seven." Each digit's value adds up to make the whole number.
Q1. In the number 58, what is the value of the digit 5?
A) 5 B) 50 C) 500
Answer: B — 50 (the 5 is in the tens place)Q2. Which number has a 3 in the tens place?
A) 13 B) 31 C) 73
Answer: B — 31 (the 3 is on the left = tens place)Q3. What is 40 + 9?
A) 49 B) 94 C) 409
Answer: A — 49 (4 tens and 9 ones)Keep practising and move on when you feel confident!