獾老闆的動物旅館要裝潢。第 1 關房間只標長和寬，孩子沿著地板拖出一排地墊、沿著牆拖出一列地墊，看出「一排幾塊、有幾排」，推出長方形面積 = 長 × 寬，再算繞一圈的周長；第 2 關用 1 立方公分積木蓋長方體模型：拖出一排、一列，再一層層往上疊，算出體積 = 一層幾個 × 幾層，也會反過來問要疊幾層；第 3 關是反向題：知道面積和長求寬、正方形的邊長、周長一樣時哪種房間面積最大，以及只用公式算的大房間和長方體。
適合年級：四年級（約 9～10 歲）。對應 108 課綱（十二年國教）數學單元：四年級「正方形和長方形的周長與面積」和「體積和立方公分」。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：孩子常把周長和面積搞混。可以問「這是要鋪滿地板（面積），還是沿著牆繞一圈（周長）？」，單位也不一樣：平方公尺和公尺。
Mr Badger’s animal hotel needs a makeover. In level 1 the rooms only show length and width: children drag one row of mats along the floor and one column up the wall, see “so many in a row, so many rows” and find area = length × width, plus the perimeter. In level 2 they build boxes from 1 cm³ blocks, laying a row, a column and then stacking layers to find volume = one layer × layers, and also how many layers make a given volume. Level 3 turns things round: find the width from the area, the side of a square, the biggest room for a given perimeter, and formula-only rooms and boxes.
Suits Grade 4 (about age 9–10) in Taiwan. Taiwan curriculum (12-year basic education) units: Perimeter and area of squares and rectangles; Volume and cubic centimetres (Grade 4). 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.