Grade 4 - Progress in Mathematics

The Abacus

The ancient Greeks and Romans used an abacus

to make computations. The abacus is still used

today in Asian cultures.

Each black bead

stands for 5 units.

Each white bead

stands for 1 unit.

A number is shown by moving the appropriate beads

to the crossbar.

5 ones 5 tens 2 hundreds

3 ones 3 tens 5 tens

4 ones 1 ten

5 ones

2 ones

5 
 3  8 50 
 30 
 4  84 200 
 50 
 10 
 5 
 2  267

Make your own abacus. Use buttons, beads, or counters.

Show each number on your abacus.

1. 39 2. 326 3. 26 4. 681 5. 78 6. 589

Hundred MillionsTen MillionsMillionsHundred ThousandsTen ThousandsThousandsHundredsTens Ones

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