Final answer:
Teddy needs 168 more small cubes to fill the box completely.
Step-by-step explanation:
To find out how many more small cubes Teddy needs, we first need to calculate the volume of the box. The volume of a rectangular box can be calculated by multiplying its length, width, and height. In this case, the box has dimensions of 7cm by 6cm by 4cm, so its volume is 7cm * 6cm * 4cm = 168cm³.
Next, we calculate the volume of one small cube. Each small cube has sides that are 1cm long, so its volume is 1cm * 1cm * 1cm = 1cm³.
To determine how many small cubes are needed to completely fill the box, we divide the volume of the box by the volume of one small cube. So, 168cm³ ÷ 1cm³ = 168.
Teddy needs 168 more small cubes to fill the box completely.