# 1-100 facts addition and subtraction practice.

Mentally adding and subtracting at least two digit numbers is important for the students' success in math. This skill allows to do verification easily with family facts, better estimation, etc.

Math Skill Builder tracks each fact family and makes sure that all facts are learned equally well.

## 1-100 Subtraction

1-100 Subtraction practice helps to train subtraction facts with the subtrahend and the difference in 1-100 range.

## Algebra

Use the Algebra feature to make the training more effective. Students will solve algebra problems only for facts they are comfortable with. It allows first to learn the facts and then to master them with the algebra feature.

Please note that the algebra feature makes 1-100 addition and subtraction training more complicated but allows to reach amazing fluency.

## Progress report

The report shows learning progress in percentage (0% - not learned, 100% - learned perfectly).
There are three levels of the report.

### Short report

1-100 subtraction: 39%

### Normal report

The normal report shows progress by the family facts. For example "Add to ?4" means add to 4,14,24,...,84,94.

1-100 subtraction. Done: 39%

 Subtract ?1 34% Subtract ?2 34% Subtract ?3 49% Subtract ?4 45% Subtract ?5 36% Subtract ?6 20% Subtract ?7 32% Subtract ?8 42% Subtract ?9 30% Subtract ?0 70%

### Detailed report

The detailed report shows the progress for each fact that we are tracking. The question mark means that there could be any number. For example ?3 means that there could be facts 3,13,23,...,83,93.

Hover the pointer over the grid chart to view the tooltip with the facts description.

+?1+?2+?3+?4+?5+?6+?7+?8+?9+?0
?1
?2
?3
?4
?5
?6
?7
?8
?9
?0

### 1-100 subtraction

Hover the pointer over the grid chart to view the tooltip with the facts description.

=?1=?2=?3=?4=?5=?6=?7=?8=?9=?0
-?1
-?2
-?3
-?4
-?5
-?6
-?7
-?8
-?9
-?0