FractionsGrades 4–5

Build a bar out of blocks

Lay Ticks, Crosses and Holds into a bar of four beats. Every block is a fraction, and the bar is only finished when they add up to exactly 1.

FractionsArithmetic

One bar is one whole thing — four beats long. Every block you drop in takes a slice of it. Keep adding until the slices add up to exactly 1, then press play.

your bar — tap a block to take it out again

does it add up to one whole bar?

¼ + ¼ + ½=1✓ one whole bar

all over eighths: 2⁄8 + 2⁄8 + 4⁄8 = 8⁄8 = 1

That is 4 beats out of 4.

1 · pick a block

2 · pick a size — drag it in, or just tap

The blocks are drawn to scale: the half block really is twice as wide as the quarter, and four times the eighth.

tempo92 BPM

Tick the four beats underneath, so you can hear the grid

or load a bar that already works

From the NSM syllabus

“Beat Blocks with Exercises — Notes, Rests & Holds”
“Compose pieces using Ticks, Crosses & Holds”

A bar is the number 1

Four beats, one whole thing. A half block eats half of it, a quarter block a quarter. That is why the notes are named after fractions — they always were.

Same total, many routes

¼ + ¼ + ½ = 1. So does ½ + ½. So do eight eighths. Different rhythms, identical sum — the bar does not care how you get there, only that you arrive at 1.

Crosses and Holds count too

A Cross is silence and a Hold lets the last note ring on — but both still take up their slice of the bar. Silence has a size. That surprises most people.

For the classroom

Learning goals

A 4/4 bar is one whole; whole, half, quarter and eighth blocks are the unit fractions 1, ½, ¼ and ⅛ of it, drawn to scale so the comparison is visual before it is symbolic.
Adding unlike fractions needs a common denominator — here every block is also written over eighths, so ¼ + ¼ + ½ becomes 2⁄8 + 2⁄8 + 4⁄8 = 8⁄8 = 1.
Rests (Crosses) and ties (Holds) occupy duration without sounding: a length can exist without an event.

Try this

1.Build one bar three different ways that each total exactly 1, and write the three sums on the board. Ask what is the same about all three answers.
2.Load '¼ + ¼ + ½', then swap the half for two quarters. Before pressing play, ask the class to predict whether the bar still fills — and why the sum did not change.
3.Put in a Cross where a Tick used to be. The sum is identical, the sound is not. Ask a student to explain the difference in their own words.