Unit 2 Reteach

Unit 2

Reteach & Review

There are 10 marshmallows in each mug and some more marshmallows on the table. How many marshmallows are there altogether?

Multiple Choice

There are 10 marshmallows in each mug and some more marshmallows on the table. How many marshmallows are there altogether?

• 3

• 5

• 35

• 8

Since each mug's value is 10 marshmallows, I need to count by 10s when I count the mugs. 10, 20, 30. Then, the value of each marshmallow is only 1 marshmallow so I need to count on by 1s. Since I already have 30 marshmallows I can count on by saying the next number. 31, 32, 33, 34, 35. I have 35 marshmallows.

Why did we count the mugs by 10s?

Why did we count the marshmallows on the table by 1s?

I spilled all my base-ten blocks! (model)

How many do you see?

Fill in the Blanks

How should we start counting?

First we count by 10s because the value of each rod is 10 units.

one hundred ninteen

what number is this?

one hundred = 100

nineteen = 19

one hundred nineteen = 119

one hundred = 100

twenty = 20

one hundred twenty = 120

34

what 2 ways can I represent this number?

34 = 3 tens, 4 ones

34 = 34 ones

2-digit numbers can be represented by tens and ones or just ones

Multiple Select

47

• 7 tens, 4 ones

• 4 tens, 7 ones

• 47 ones

• 47 tens

47 = 4 tens, 7 ones

47 = 47 ones

2-digit numbers can be represented by tens and ones or just ones

What symbol should I use to compare these two numbers?

The alligator always eats the number with a greater value.

What symbol goes in between to compare these two numbers?

Multiple Choice

What symbol compares these two numbers?

• <

• >

• =

95 has a greater value, so the alligator is going to eat it!

Great work!

We're all done,

come back to Zoom :)