1 ✨ Spark
A shop has 3 boxes of 100 pencils, 4 packets of 10 and 6 loose pencils. How can you count them all quickly?
Think about this for a moment before you start.
2 🧊 3D Explore
Turn the scene, tap the objects and answer. Easy, Medium and Challenge are the three checkpoints.
➗ Numbers and place value
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3 📖 Explain
A 3-digit number has hundreds, tens and ones. In 346 the 3 means 3 hundreds, the 4 means 4 tens and the 6 means 6 ones.
Ten ones make one ten, and ten tens make one hundred. So the place of a digit tells its value: the same 4 is worth 4 in the ones place, 40 in the tens place and 400 in the hundreds place.
To compare two numbers, look at the hundreds first. If they are equal, look at the tens, then the ones.
At a ration shop, rice comes in 100 kg sacks, 10 kg bags and loose kilograms. 2 sacks, 3 bags and 5 kg make 235 kg.
✗ In 507 the 0 means nothing, so I can leave it out.
✓ The 0 keeps the tens place empty. Without it, 507 would become 57.
📒 Glossary
- place value
- what a digit is worth because of where it stands
- hundreds
- groups of one hundred
- expanded form
- 346 = 300 + 40 + 6
4 ✍️ Practice
Play Medium and Challenge in the 3D scene. The bars show how many you got right the first time.
My mastery (right first time / played)
- Easy0 / 0
- Medium0 / 0
- Challenge0 / 0
5 🏡 Real-life task
Try this at home or at school, then check the suggested answer.
Scenario A shopkeeper has 3 boxes of 100 pencils, 4 packets of 10 and 6 loose pencils. How many pencils does she have?
Show a suggested answer
346 pencils: 3 hundreds + 4 tens + 6 ones = 300 + 40 + 6 = 346.
Make bundles of 10 sticks and bigger bundles of 100. Show your house number or your school's pin code digits with them.
6 💭 Reflect
Think, then answer in your own words. Your notes stay on this device.
Observation In the 3D scene, build 243 with blocks. What do you notice about the number of rods and the tens digit?
Show a suggested answer
243 needs 2 flats for 2 hundreds, 4 rods for 4 tens and 3 cubes for 3 ones. The number of rods is the tens digit: each kind of block matches one digit.
Explain / create Teach a friend why 406 and 460 are different numbers. Use blocks or a drawing.
Show a suggested answer
406 is 4 hundreds, 0 tens and 6 ones; 460 is 4 hundreds, 6 tens and 0 ones. The 6 is in a different place, so it is worth 6 in one number and 60 in the other. 460 is bigger.