Cogito
Grade 1 Math · Chapter 1 · Lesson 7
One More, One Less
Find one more or one less without recounting.
10 problems · about 10 minutes · 1.OA.C.5, 1.NBT.A.1
What this lesson teaches
The child finds one more and one less than any number to 10 by using the structure of the number, not by recounting from one.
- One more is the next number.
- One less is the number before.
- You do not need to count from one.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
4 problemsReview — Partners to Ten: How many more would make ten?
Answer 6
Why 4 and 6 are partners to ten.
Review — All the Ways to Make 8 and 9: 5 and what make 8?
Answer 3
Why 5 and 3 make 8.
Review — All the Ways to Make 6 and 7: 4 and what make 6?
Answer 2
Why 4 and 2 make 6.
Review — Number Bonds: The whole is 6. One part is 2. What is the other part?
Answer 4
Why 2 and 4 make 6.
Warm Up
Straightforward practice. Get the method working first.
3 problemsWhat is one more than 4?
Answer 5
Why One more than 4 is 5.
What is one less than 7?
Answer 6
Why One less than 7 is 6.
What is one more than 8?
Answer 9
Why The next number after 8.
Build It Up
The same ideas with more to keep track of.
1 problemWhat is one less than 5?
Answer 4
Why One square back from 5.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
2 problemsWhat is one more than 9?
Answer 10
Why The next number after 9.
Building a Tower: Leo has a tower of 6 blocks. He adds 1 more. How tall is it now?
Answer 7 blocks
Why One more than 6 is 7.