Addition using a Chip Abacus

1
Using a Chip Abacus to Show Subtraction
2
Subtraction using a Chip Abacus
Hundreds
Tens
Ones
On your mat lay out the chips for the Minuend only
249 - 25
3
Subtraction using a Chip Abacus
Hundreds
Tens
Ones
Now remove or take away 5 chips from the Ones
column
249 - 25
Remove from the mat.
4
Subtraction using a Chip Abacus
Hundreds
Tens
Ones
Remove or take away 2 chips from the Tens column
249 - 25
Remove from the mat.
5
Subtraction using a Chip Abacus
Read the answer on the mat, there are 2 in the
Hundreds column, 2 in the Tens column and 3 in
the Ones column.
Hundreds
Tens
Ones

• 249
• 25
• 223

6
Subtraction using a Chip Abacus
Hundreds
Tens
Ones
On your mat lay out the chips for the Minuend only
121 - 25
7
Subtraction using a Chip Abacus
Since you do have enough chips in the Ones column
to remove 5 chips you must move on of the chips
in the Tens column over.
Hundreds
Tens
Ones
121 - 25
8
Subtraction using a Chip Abacus
Now there are 11 chips in the Ones column.
Hundreds
Tens
Ones
121 - 25
9
Subtraction using a Chip Abacus
Remove the 5 chips from the Ones column.
Hundreds
Tens
Ones
121 - 25
Remove from the mat
10
Subtraction using a Chip Abacus
Now you need to remove 2 chips from the Tens
column. Since there are not enough chips, one
chip from Hundreds column will have to move over.
Hundreds
Tens
Ones
121 - 25
11
Subtraction using a Chip Abacus
There are 11 chips in the Tens column. Remove
the 2 chips from the Tens column.
Hundreds
Tens
Ones
121 - 25
Remove from the matt.
12
Subtraction using a Chip Abacus
Now read the answer. There are 9 chips in the
Tens column and 6 chips in the Ones column.
Hundreds
Tens
Ones

• 121
• 25
• 96

13
Subtraction using a Chip Abacus
Now you try these problems 159 - 28 145 - 23
349 - 258 43 - 25 257 - 149 244 - 156