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LEGO Missing Piece Checker

Rule out the usual hiding places first. If the piece really is gone, check the set piece by piece and leave with the element ID LEGO asks for, or a link to buy the part.

FLL WORLD Class: Learning Unleashed Challenge Kit

Checking

45800 FLL WORLD Class: Learning Unleashed Challenge Kit

2,090 pieces in 325 part and color combinations, plus 2 minifigures.

LEGO counts 2,101 pieces. This inventory comes from a separate parts catalog and lists 2,098, including the 8 parts inside the minifigures; the two do not always count the same elements, so their totals differ. Spare parts are counted in neither figure.

Before you call it missing

Builders who report a missing piece often find it in one of these places. Tick each one off as you look.

Every bag and the box. Shake out each bag, check its corners and seams, and look inside the empty box.
Inside what you have built. Small pieces lodge inside tubes, under plates and between studs. Turn the model over and look.
The last few steps. Compare each recent step with its parts callout. A piece used in the wrong place earlier leaves you one short later.
Look-alike colors. 3 parts in this set come in two colors that are easy to mix up; they are listed below.
The spare pieces. This set comes with 4 spare pieces, marked on each row of the checklist. One may be the piece you need.
The floor and your building area. Check under furniture, the chair and the edges of your building surface.

Look-alike colors in this set

These parts appear in this set in two colors that are easy to confuse. If you are one short in one color, check whether it went in where the other color belongs. Each color has its own element ID in the parts list at the back of the instructions.

Tile Round 1 x 1 White ×4 Trans-Clear ×1 Trans-Clear is see-through: hold the piece up to a light.
Technic Beam 1 x 7 Bent (4 - 4) Thick Black ×3 Dark Bluish Gray ×6 Black is darker than Dark Bluish Gray.
Technic Beam 2 x 4 L-Shape Thick Black ×16 Dark Bluish Gray ×3 Black is darker than Dark Bluish Gray.

Piece checklist

Tan 42 pieces

Technic Axle 4 with Centre Stop Tan Part 99008 Element 4666999 ×2
Technic Axle Pin without Friction Ridges Lengthwise Tan Part 3749 Element 4666579 or 4186017 ×27
Technic Pin 3/4 Tan Part 32002 Element 6663097 or 6013938 ×4
Technic Pin Long without Friction Ridges Tan Part 32556 ×8
Tile 2 x 2 with Street Level Map and Red 'X' Print Tan Part 3068bpr0226 Element 6029848 ×1

Flat Silver 20 pieces

Hose, Ribbed 7mm D. 18L / 14.4cm Flat Silver Part 78c18 Element 6491958 or 4620068 ×17
Hose, Ribbed 7mm D. 9L / 7.2cm Flat Silver Part 78c09 Element 6600684 or 6081344 ×2
Tile Round 1 x 1 with Gauge and Red Pointer Print Flat Silver Part 98138pr0012 Element 6287877 or 6030333 1 spare in the box ×1

Dark Tan 18 pieces

Technic Axle 3 with Stud Dark Tan Part 6587 Element 6031821 or 6013821 ×18

Lime 16 pieces

Brick 1 x 1 with Oranges Print [Juice Carton] Lime Part 3005pr9993 Element 4622047 ×1
Brick Round 2 x 2 Dome Top, Hollow Stud Lime Part 30367c Element 4279734 ×12
Brick Sloped 30° 1 x 1 x 2/3 (Cheese Slope) Lime Part 54200 Element 4504372 or 4298015 ×1
Technic Wedge Belt Wheel [aka Pulley] Lime Part 4185 Element 6335116 or 4494219 ×2

Reddish Brown 10 pieces

Equipment Brush / Push Broom Reddish Brown Part 3836 Element 4211157 ×1
Plate 1 x 1 Reddish Brown Part 3024 Element 4221744 ×4
Plate 1 x 2 Reddish Brown Part 3023 Element 4211150 ×1
Plate 1 x 3 Reddish Brown Part 3623 Element 4211152 ×2
Tile 1 x 2 with Groove Reddish Brown Part 3069b Element 4211151 ×2

Trans-Clear 3 pieces

Dish 4 x 4 Inverted [Radar] Trans-Clear Part 3960 Element 4166082 or 4125240 ×1
Equipment Bottle / Erlenmeyer Flask with Trans-Bright Green Fluid Pattern Trans-Clear Part 93549pat0001 Element 6530023 or 6447576 ×1
Tile Round 1 x 1 Trans-Clear Part 98138 Element 6514191 or 6274738 Also in White ×1

Trans-Red 3 pieces

Light Cover 1 x 1 Round with Internal Bar / Bionicle Barraki Eye Trans-Red Part 58176 Element 6507867 or 6171762 ×3

Trans-Bright Green 2 pieces

Light Cover 1 x 1 Round with Internal Bar / Bionicle Barraki Eye Trans-Bright Green Part 58176 Element 6507869 or 6171864 ×2

Trans-Dark Blue 2 pieces

Light Cover 1 x 1 Round with Internal Bar / Bionicle Barraki Eye Trans-Dark Blue Part 58176 Element 6328198 or 6171763 ×2

Trans-Orange 2 pieces

Light Cover 1 x 1 Round with Internal Bar / Bionicle Barraki Eye Trans-Orange Part 58176 Element 6507868 or 6171764 ×2

Dark Red 1 piece

Helmet Fire Dark Red Part 3834 Element 4650879 ×1

Medium Azure 1 piece

Tile 1 x 2 with Smart Phone with Phone, Mail, Speech Bubble, Star, Flower, Note, Play Button and Sound Level Print Medium Azure Part 3069bpr0130 Element 6038640 ×1

Pearl Gold 1 piece

Weapon Lightsaber Hilt with Bottom Ring Pearl Gold Part 64567 Element 6003147 ×1

Minifigures 2 figures

White Torso, Medium Blue Legs, Reddish Brown Hair Minifigure, checked as a whole figure ×1
Red Torso, Black Legs, Black Hair Minifigure, checked as a whole figure ×1

Tick each piece as you find it, or mark it missing.

When a piece really is missing

Ask LEGO

LEGO takes requests for pieces missing from a new set through its customer service site. The form asks for the set number and each piece's element ID, the number printed beside the piece in the parts list at the back of the instructions. This checker lists both.

Request a replacement from LEGO

Buy the piece

Mark a piece missing and your list links it to an eBay search for that part, which also covers pieces from older or second-hand sets.

Keep a record

Copy or download your missing list (the CSV opens in any spreadsheet), or print the whole checklist and tick pieces off on paper. Your marks stay in this browser, so you can check a big set over several sittings.