B1.1 Reading and building numbers to 1000
A three-digit number is hundreds, tens and ones: 675 is 6 hundreds, 7 tens and 5 ones. Expanded form: 600 + 70 + 5. We meet these on odometers, page counts and price tags.
Example
Build 675 with base-ten blocks, then say it in expanded form.
- 6 flats = 600. 7 rods = 70. 5 cubes = 5.
- 600 + 70 + 5 = 675.
- A zero holds its place: 305 has 0 tens, and the 0 keeps the 3 in the hundreds.
B1.2 Comparing and ordering to 1000
Example
Order 755, 655, 690 from least to greatest.
- Compare hundreds first, then tens, then ones.
- 655 and 690 share hundreds; 655 has fewer tens, so it is smaller.
- 755 has one more hundred: the greatest.
- Least to greatest: 655, 690, 755.
- Hundreds first.
- Tie? Tens.
- Tie again? Ones.
- Write with < or >, or list least to greatest.
B1.3 Rounding to the nearest ten or hundred
Rounding finds the closest ten or hundred. Look at the digit one place to the right of where you are rounding: 5 or more rounds up, 4 or less rounds down.
Example
Round 675 to the nearest hundred, then to the nearest ten.
- Nearest hundred: neighbours 600 and 700. Tens digit is 7: 5 or more goes up, 4 or less goes down.
- Nearest ten: neighbours 670 and 680. Ones digit is 5: same rule.
- Rounding is for estimating: "about 6 hundred".
B1.4 Counting by 50s, 100s and 200s
Example
Count by 100s to 1000.
- 100, 200, 300, 400 … each jump adds 100.
- By 100s, only the hundreds digit moves. By 50s it goes 50, 100, 150.
- By 200s you reach 1000 in five jumps.
B1.5 Place value, many ways
Example
Show 675 in four ways.
- Standard form: 675.
- Expanded form: 600 + 70 + 5.
- Words: say the hundreds, then the tens and ones.
- Blocks: 6 flats, 7 rods, 5 cubes — or 5 flats and 17 rods, regrouped.
B1.6 Fair shares up to 20 items
Sharing can give whole numbers, mixed numbers (like 3 and a half) or just a fraction. Draw the items, deal them out, then split any leftovers into equal parts.
Example
Share 12 stickers among 3 friends. Then share 7 pancakes between 2.
- 12 among 3: each gets 4. A whole number.
- 7 between 2: 3 each, 1 left. Cut it in half: 3 and a half each. A mixed number.
- More sharers, smaller share: 12 among 6 gives 2; among 3 gives 4.
B1.7 Equivalent fractions
Example
Which pairs are equal: one fourth and two eighths? one third and two sixths? one fifth and two tenths?
- Cut each fourth in two: 4 parts become 8. One fourth = two eighths.
- Cut each third in two: one third = two sixths.
- Cut each fifth in two: one fifth = two tenths. Same whole, smaller pieces, more of them.
Summary
- Hundreds, tens, ones to 1000; expanded form.
- Compare from the hundreds down.
- Round: 5 or more up, 4 or less down.
- Shares can be whole, mixed or a fraction; equal pieces make equal fractions.