Cogito
Grade 1 Math · Chapter 10 · Lesson 5
Comparing Numbers to 100
Compare bigger numbers the same way as before.
10 problems · about 12 minutes · 1.NBT.B.3
What this lesson teaches
The child compares two-digit numbers to 100 using the symbols for greater than, less than, and equal to.
- Compare the tens first, even with big numbers.
- If the tens tie, compare the ones.
- Then write >, <, or =.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
4 problemsReview — Counting to 120: What comes right after 104?
Answer 105
Why After 104 comes 105.
Review — Numbers to 100: How many ones are in 86?
Answer 6
Why 86 is 8 tens and 6 ones.
Review — Two-Bar Tape Diagrams: Bars of 15 and 8. What is the difference?
Answer 7
Why 15 − 8 = 7.
Review — How Many More? How Many Fewer?: 10 birds and 6 cats. How many more birds?
Answer 4
Why 10 − 6 = 4.
Warm Up
Straightforward practice. Get the method working first.
3 problemsWhich is greater, 38 or 41?
Answer 41
Why 41 has more tens.
Which symbol makes this true: 62 ? 71
Answer <
Why 62 is less than 71.
Which is greater, 56 or 65?
Answer 65
Why 6 tens beats 5 tens.
Build It Up
The same ideas with more to keep track of.
1 problemWhich is greater, 91 or 89?
Answer 91
Why 9 tens beats 8 tens.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
2 problemsWhich symbol makes this true: 47 ? 47
Answer =
Why The numbers are the same.
Two Jars: One jar has 82 beans. Another has 79. Which has more?
Answer 82 beans
Why 82 has 8 tens, so it is greater.