帝雉廠長的茶廠要出貨，孩子幫忙包裝茶葉罐。第 1 關把長方體罐子的 6 個面拖到十字形的展開圖上（按「轉一轉」看背面、底面和左邊），相對的兩面放好會變成同一個顏色，再算出包裝紙一共幾平方公分。第 2 關的罐子有罐壁，孩子用 ▼ ▲ 量出裡面的長、寬、高（每一邊都要扣兩次罐壁），再算能裝幾毫升。第 3 關用體積和底面反推罐子要做幾公分高，也練習把立方公分換成公升（12000 立方公分 = 12 公升，1200 立方公分 = 1.2 公升）。
適合年級：五年級（約 10～11 歲）。對應 108 課綱（十二年國教）數學單元：五年級「長方體和正方體的體積、表面積和容積」。各版本教科書的單元順序不同，完整對照請看國小數學課綱對照表。免費、無廣告、不用註冊，手機、平板、電腦打開就能玩，題目有注音，也會念出來。
陪玩小提醒：可以拿家裡的紙盒拆開看看，相對的兩面一樣大，所以表面積只要算 3 種面再乘 2。孩子算容積時常直接用外面的長寬高，提醒他茶葉是裝在「裡面」的。
Mikado Pheasant’s tea factory is shipping out and children help wrap the tins. In level 1 they drag the 6 faces of a cuboid tin onto a cross-shaped net (Turn shows the back, bottom and left), each opposite pair turns the same colour, and then they work out the paper needed in square cm. In level 2 the tin has thick walls: they use ▼ ▲ to measure the inside length, width and height (taking the wall off both sides) and then the capacity in mL. Level 3 finds how tall a tin must be from its volume and base, and converts cubic cm to litres (1200 cubic cm = 1.2 litres).
Suits Grade 5 (about age 10–11) in Taiwan. Taiwan curriculum (12-year basic education) unit: Volume, surface area and capacity of cuboids and cubes (Grade 5). Free with no ads and no sign-up, in Traditional Chinese with zhuyin and in English, read aloud. See the Taiwan elementary maths curriculum map.