Decimal Builder

Choose a mode

Fill the ones, tenths and hundredths jars with the − / + buttons (each jar's sand level shows that digit), then press Check

3D math game · Best for grades 4-5

Decimal Builder

Build a decimal number by filling sand jars in a lab

Filling ones, tenths, and hundredths highlights the value of each digit in a decimal number.

What students practice

The game builds understanding of Decimals. Fill the ones, tenths and hundredths jars with the − / + buttons (each jar's sand level shows that digit), then press Check

ones, tenths, and hundredths in decimal numbers.

How to use it at home or in class

Students build the number through digits and place value.

Each digit’s value becomes easier to understand.

Use it for individual practice, paired work, or a short class demonstration before worksheets.

Start with the game above, then continue with written practice to reinforce the skill.

Common questions

Who is this game for?
This game is designed for grades 4-5 students who want to practice Decimals interactively.
Is the game free?
Yes. Students can play and practice on the site without signing up.
What is the best way to practice?
Start with Practice mode, solve a few rounds slowly, then switch to a short Quiz for self-checking.