Fractions and decimals.

Step 1 of 5

Parts of a whole

The bar is one whole. The Denominator, the number under the line, says how many equal pieces it is cut into, and the Numerator, the number above the line, says how many of the pieces are shaded. $\frac{3}{4}$⁠ is three pieces out of four.

The fraction bar is also a division sign: $\frac{3}{4} = 3 \div 4$$\frac{3}{4} =$$3 \div 4$⁠. That is how a fraction becomes a decimal. Answer, then drag Look inside to see the decimal and the percentage.

Step 2 of 5

Same part, different names

One fraction can be written in many ways: half a bar is two quarters, and three sixths as well. When you multiply the numerator and the denominator by the same number, the pieces get smaller, there are more of them, and the shaded part stays the same length.

Step 3 of 5

Adding fractions

The two bars are cut into pieces of different sizes: halves and thirds. Before you add, both have to be cut into pieces of the same size. Predict the sum, then watch the new cut.

Step 4 of 5

A common denominator

A common denominator is a number both denominators divide into, and usually you pick the smallest. For $4$⁠ and $6$⁠ it is $12$⁠, because $4 \times 3 = 12$⁠ and $6 \times 2 = 12$⁠. Multiply each numerator by the same number as its denominator.

Step 5 of 5

Comparing decimals

The first digit after the point counts tenths, and the second hundredths. On the board $0.5$⁠ is $\frac{5}{10}$⁠ and $0.25$⁠ is $\frac{25}{100}$⁠. Look at the length of the shading, and once you answer drag Look inside to cut both bars into hundredths.