NCERT Solutions Ganita Prakash (Part 2) Chapter 2 Figure it Out (2)

Using the token interpretation, find the values of: (a) 3 × (– 2) (b) (– 5) × (– 2) (c) (– 4) × (– 1) (d) (– 7) × 3

If 123 × 456 = 56088, without calculating, find the value of: (a) (– 123) × 456 (b) (– 123) × (– 456) (c) (123) × (– 456)

Try to frame a simple rule to multiply two integers. times each of these token sets. That is, place each set into the empty bag 4 times. What integer do we get as the final answer in each case? Do we get different answers because the sets look different, or the same answer because they all represent – 2? Check this for 5 × 4, by taking different token sets corresponding to 4. We have seen that – 4 × 2 is the number obtained by removing 2 positive tokens from the empty bag 4 times. We know that removing or subtracting a number is the same as adding its inverse. Using this, can – 4 × 2 be defined through a process of addition of tokens instead of removal of tokens? Since removing 2 positive tokens is the same as adding 2 negative tokens, – 4 × 2 can also be obtained by adding 2 negative tokens to the empty bag 4 times.