Cogito
Grade 1 Math · Chapter 10 · Lesson 4
Counting to 120
Keep counting past 100.
10 problems · about 12 minutes · 1.NBT.A.1
What this lesson teaches
The child counts, reads, and writes numbers to 120, starting from any number, and handles the 100 boundary.
- Counting keeps going past 100.
- After 100 comes 101, then 102.
- You can start counting from any number.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
4 problemsReview — 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.
Review — Telling Time to the Half Hour: How many minutes is half an hour?
Answer 30
Why Half an hour is 30 minutes.
Warm Up
Straightforward practice. Get the method working first.
3 problemsWhat comes right after 104?
Answer 105
Why After 104 comes 105.
What comes right before 111?
Answer 110
Why Before 111 comes 110.
What comes after 99?
Answer 100
Why Ten tens.
Build It Up
The same ideas with more to keep track of.
1 problemWhat comes after 100?
Answer 101
Why A new row starts.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
2 problemsWhat comes after 119?
Answer 120
Why The last square.
Counting Steps: Ana has counted 109 steps. What is the next number?
Answer 110
Why After 109 comes 110.