Cogito
Grade 1 Math · Chapter 4 · Lesson 2
Ten and Some More
Every teen number is a ten with a few left over.
10 problems · about 11 minutes · 1.NBT.B.2.b
What this lesson teaches
The child builds teen numbers as one full ten plus some ones.
- Every teen number holds one full ten.
- The rest are loose ones.
- 10 and 3 is 13.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
5 problemsReview — Ten Ones Make One Ten: How many ones are in one ten?
Answer 10
Why One ten is made of ten ones.
Review — Adding and Subtracting to Ten: 7 − 2 = ?
Answer 5
Why 7 − 2 = 5.
Review — Subtracting From Ten: 10 − 6 = ?
Answer 4
Why 10 − 6 = 4.
Review — Taking Nothing and Taking All: 10 − 10 = ?
Answer 0
Why Take all away and none are left.
Review — Fact Families: You know 4 + 5 = 9. What is 9 − 4?
Answer 5
Why Same fact, read the other way.
Warm Up
Straightforward practice. Get the method working first.
3 problems10 + 2 = ?
Answer 12
Why 10 + 2 = 12.
10 + 9 = ?
Answer 19
Why 10 + 9 = 19.
10 + 4 = ?
Answer 14
Why Ten and four.
Build It Up
The same ideas with more to keep track of.
1 problem10 + 7 = ?
Answer 17
Why Ten and seven.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
1 problemCounting Buttons: Leo has one full ten of buttons and 5 loose ones. How many buttons?
Answer 15 buttons
Why 10 + 5 = 15.