Counting hundreds

Version 0.2 · expanded edition · expert review pending Standards alignment: pending verification. Written in the style of common primary school assessments. No exam result is promised.

Student lesson

Words to know

1. Discover: a farmer’s sacks

A farmer packs 100 groundnuts in each bag. He has 5 bags. How many groundnuts does he have? Count the bags: 100, 200, …

2. Understand: counting hundreds

Ten tens make one hundred. We write it 100. Counting in hundreds goes: 100, 200, 300, 400, 500, 600, 700, 800, 900, 1,000.

Ten hundreds make one thousand, written 1,000. The number 300 is 3 hundreds. The number 800 is 8 hundreds.

A hundred looks like a flat square of ten rows of ten. A thousand looks like ten of those flats stacked together.

Idea 1: Ten tens

Ten tens make 100. We write one hundred as 100. A flat of 100 squares is the same as 10 rods of ten.

Idea 2: Count in hundreds

Count: 100, 200, 300, 400, 500, 600, 700, 800, 900, 1,000. Each step adds one hundred.

Idea 3: A thousand

Ten hundreds make 1,000 (one thousand).

Why? 10 tens = 100 and 10 hundreds = 1,000. Each place is ten times the one before.

3. Worked examples

Example 1 (I show you): Count on

Count in hundreds: 300, 400, __.

1. Add 100 each time.

Answer: 500

Example 2 (We do it together): Write as a number

Write 7 hundreds as a number.

1. 7 hundreds is 7 × 100.
2. Write 7 and then two zeros.

Answer: 700

Example 3 (You try): Add hundreds

A shop has 4 boxes of 100 and 3 boxes of 100. How many items altogether?

Did you know?

A thousand is a big number. Ten thousand children can fill a large stadium.

Why this matters

Counting in hundreds helps us read big numbers, such as prices and distances.

4. Explore: hundred flats

You need squared paper and a pencil.

1. Draw a square of 10 rows with 10 dots in each row.
2. Count the dots by tens: 10, 20, …, 100.
3. Draw 3 such squares and count 100, 200, 300.
4. Write each number in words and digits.

5. Practise

Say it in a sentence

Use these starters when you talk about the lesson. Say them out loud.

• 10 tens make ___.
• 10 hundreds make ___.
• After ___ comes ___.
• ___ hundreds is written ___.

Guided practice

Independent practice

Level 1: Start

1. Count in hundreds from 100 to 1,000.
2. What is 7 hundreds written as a number?
3. What comes after 600?
4. How many tens in 100?
5. Write 900 in words.

Level 2: Grow

1. Count back: 500, 400, __, __.
2. How many hundreds are in 800?
3. Write 3 hundreds as a number.

Level 3: Stretch

1. 8 boxes hold 100 pens each. How many pens?
2. What is 1,000 − 100?
3. Kofi writes 5 hundreds as 50. What is wrong?

Answers are in the answer key below. Try first, then check.

6. Apply: everyday mathematics

Each box holds 100 pencils. A school buys 6 boxes. How many pencils?

Another one. A farm packs 100 eggs in each tray. It fills 6 trays. How many eggs?

7. Common mistakes

8. Lesson summary and revision card

9. Check and master

Answer all 14 questions. You will see feedback after each one.

Show my result

10. Key takeaways

• 10 tens = 100.
• 10 hundreds = 1,000.
• Count in hundreds.

11. Next lesson

Next lesson: Numbers to 1,000. Keep going with the next idea in this course.

Exam practice

These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.

1. How many tens make 100? [1 mark]
2. Count in hundreds from 300 to 800. [2 marks]
3. Write six hundreds as a number. [1 mark]
4. A truck carries 5 boxes of 100 bricks. How many bricks? [2 marks]
5. Ali says 10 hundreds make 100. Is he right? Explain. [2 marks]

Total: 8 marks.

Printable worksheet

1. Tens in 100?
2. 6 hundreds as a number?
3. Next: 300, 400, __
4. Hundreds in 1,000?
5. Write 800 in words.
6. 10 tens = ___.
7. What comes after 600?
8. 4 hundreds + 4 hundreds = ___.
9. Write 900 in words.
10. 1,000 − 100 = ___.

Homework

Find something you can count in hundreds at home (for example 100 beans in a bowl). Show 300.

Answer key and marking scheme

Practice answers: Worksheet: 1 10; 2 600; 3 500; 4 10; 5 eight hundred.

Quiz answers: 1 A, 2 B, 3 C, 4 A, 5 B, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 C, Challenge 2 C.

Extra worksheet answers (items 6 onward): 6 100; 7 700; 8 800; 9 nine hundred; 10 900.

Independent practice answers. Level 1: 1 100, 200, 300, 400, 500, 600, 700, 800, 900, 1,000; 2 700; 3 700; 4 10; 5 nine hundred. Level 2: 1 300, 200; 2 8; 3 300. Level 3: 1 800; 2 900; 3 5 hundreds is 500. 50 is 5 tens..

Mastery and remediation

Proposed Courseversity thresholds for this page: Bronze = at least 8 of 12 core questions correct; Silver = all 12; Gold = all 12 plus both challenge questions. A badge is never a full record of progress.

If a learner struggles

1. Find the misconception: Saying 10 tens is 1,000. 10 tens make 100. 10 hundreds make 1,000.
2. Explain another way: use real objects first, then pictures.
3. Show a simpler example: Use ten bundles of ten sticks to build 100 and count by tens.
4. Guided practice: work through one example together and let the learner try the next one.
5. Reassess: use the quiz again or the worksheet.
6. Move on when the learner shows Silver-level evidence independently.

For parents and guardians

In this lesson your child learns that 10 tens make 100 and counts in hundreds. You do not need to be good at mathematics to help.

• Count in hundreds when you pass money or objects.
• Make 10 piles of 10 beans and join them to make 100.
• Ask: how many hundreds are in 600?
• Ask “how do you know?” after each answer, and listen.
• Praise effort, not only right answers. Mistakes are how we learn.
• Ten to fifteen minutes a day is better than one long session.

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