Chapter 11 The Study Of Numbers Up To 1000—Ii
pink rods, and in the opposite corner 52, made with five yellow rods side by side. In the remaining spaces, which are two equal rectangles, either four yellow rods or five pink rods are placed.
FIG. 83. Once the equal rectangles have been measured and found to be either 4 × 5 or 5 × 4, the rods in the rectangles may be removed to allow the blue base of 92 underneath to set the rectangles into sharper relief. An attempt should then be made to read the pattern. The blue square underneath, (9)2, is seen to be equal to (4 + 5)2. The two equal rectangles are each 4 × 5, or its equivalent 5 × 4. Bearing these two facts in mind, the patterns can be read:
Published on Nov 18, 2009