Equal Halves and Fourths — Find the Fair Shares | Grade 1 Geometry

About this activity

Four cards lie on a shelf, each the same shape cut into pieces. The child hangs a card on a mobile that has one hook for every share. Cardboard weighs by its size, so the mobile measures what "equal" means: fair shares hang perfectly level, an unfair cut tips the bar, extra pieces drop into a spare tray, and missing pieces leave a hook bare. A pin holds the bar still until Check pulls it out and the mobile swings to its true tilt.

The first level asks for halves and fourths of circles, squares and rectangles. The second adds thirds on a bar pivoted at a third, and fair shares that look different, such as fourths cut corner to corner or a triangle cut into three from its center. The third level turns it around: three mobiles carry name plates for one half, one third and one fourth, and the child hangs a card with one shaded share on the mobile it belongs to. When every share is equal, a stacked fraction appears on each piece.

After a first miss the mobile shows what is wrong: it tips, a hook stays empty, or pieces land in the tray, and the heaviest share glows. After a second miss the springs under the hooks are measured against a dashed fair line, so the share that is too big stands out; in the third level the mobile with the right number of hooks bobs. Aligned to Common Core 1.G.A.3 (halves and fourths), with thirds from 2.G.A.3. No timer and no score.

What's inside this activity

• Designed for Grade 1 learners (ages about 6–7)
• Common Core strand: Geometry
• Aligned to Common Core standard 1.G.A.3

How to play

Tap a card, or drag it onto the mobile, to hang it. Tap the mobile to take the card down.

Press Check to pull the pin. Fair shares hang level; an unfair card tips the bar.

Pieces in the spare tray mean too many pieces; a bare hook means too few.

In "Name the share", tap the card, then tap the mobile whose name plate matches the shaded share.

In the settings choose the level (Halves and fourths · Thirds and fair shares · Name the share) and turn the spirit level on the bar on or off.

What your child practices

• Telling equal shares from unequal ones by their size, not by the number of lines
• Matching the number of equal shares to halves, thirds and fourths
• Seeing that equal shares of the same whole can look different
• Naming one share as one half, one third or one fourth

Learning goals

Recognize circles, rectangles and other shapes cut into two, three or four equal shares, and tell when shares are not equal.

Describe the shares as halves, thirds and fourths (quarters).

Recognize that equal shares of identical wholes need not have the same shape.

Name one share of a whole as one half, one third or one fourth.