Cogito
Grade 2 Math · Chapter 3 · Lesson 2
Building Numbers to 1,000
Every three-digit number is hundreds, tens, and ones.
10 problems · about 12 minutes · 2.NBT.A.1
What this lesson teaches
The child builds and reads any number to 1,000 as a count of hundreds, tens, and ones.
- Every three-digit number is hundreds, tens, and ones.
- The place a digit sits in decides its job.
- Ten hundreds make one thousand.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
3 problemsReview — A New Unit: The Hundred: How many tens are in one hundred?
Answer 10
Why Ten tens make a hundred.
Review — Adding and Subtracting on a Number Line: Start at 26 and jump forward 20. Where do you land?
Answer 46
Why 26 + 20 = 46.
Review — From Ruler to Number Line: How far is 13 from 0 on a number line?
Answer 13
Why 13 is 13 units from 0.
Warm Up
Straightforward practice. Get the method working first.
3 problems6 hundreds, 0 tens and 3 ones is which number?
Answer 603
Why 603 has no tens.
In 482, which digit tells the hundreds?
Answer The 4
Why The 4 counts hundreds.
In 617, how many tens are there?
Answer 1
Why The middle digit.
Build It Up
The same ideas with more to keep track of.
1 problem7 hundreds, 2 tens and 9 ones is which number?
Answer 729
Why 700 and 20 and 9.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
3 problemsHow many hundreds make one thousand?
Answer 10
Why Bundle ten of them.
The Library: A shelf holds 4 hundreds, 3 tens, and 6 ones of books. How many books?
Answer 436 books
Why 4 hundreds, 3 tens and 6 ones is 436.
Same Digits: Which is greater, 385 or 583?
Answer 583
Why 583 has 5 hundreds; 385 has only 3.