Math Skill: Understanding 11 to 19
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Understanding 11 to 19

This topic assumes you know how to count.
To review, please see the topic Counting Objects.

There are blocks of ones.

 3 blocks

There are blocks of ten.

 or

Examples:
Complete the equation (e.g., 11 = 10 + 1).

 = +

= +

 = +

= +

 = +

= +

Examples: Equations only
Complete the equation with the form tens + ones (e.g., 10 + 5).

15 = +
11 = +
19 = +

### Complexity=1, Mode=ct

Count the number of shaded squares.

### Complexity=1, Mode=eqv

Complete the equation (e.g., 11 = 10 + 1).
1.
 = +

= +

2.
 = +

= +

### Complexity=1, Mode=eq

Complete the equation with the form tens + ones (e.g., 10 + 5).
 1.   12 = + 2.   14 = +

### Complexity=2, Mode=eq

Complete the equation with the form tens + ones (e.g., 10 + 5).
 1.   55 = + 2.   48 = +

### Complexity=1, Mode=ct

Count the number of shaded squares.
1

Solution
There is one block of ten and 6 ones.
 # Tens # Ones 1 6
2

Solution
There is one block of ten and 3 ones.
 # Tens # Ones 1 3

### Complexity=1, Mode=eqv

Complete the equation (e.g., 11 = 10 + 1).
1
 = +

= +

Solution
 1 block of tens + 8 blocks of ones = 10 + 8 = 18
2
 = +

= +

Solution
 1 block of tens + 7 blocks of ones = 10 + 7 = 17

### Complexity=1, Mode=eq

Complete the equation with the form tens + ones (e.g., 10 + 5).