Try some yourself

Activity 56

Evaluate each of the following and give an example from everyday life to illustrate the sum (e.g. Thomas’s piggy bank).

  • (a) 4 − 6

  • (b) 3 + 5

  • (c) 4 + 7

  • (d) 5 + 8

Answer

  • (a) 4 − 6 = 10.

  • If you have an overdraft of £4 and take out £6 you have an overdraft of £10.

  • (b) 3 + 5 = 3 − 5 = 2.

  • Thomas’s bank has £3 plus a £5 IOU, which is equivalent to a £2 IOU.

  • (c) 4 + 7 = 4 − 7 = 11.

  • A debit of £4 plus a debit of £7 is equivalent to a debit of £11.

  • (d) 5 + 8 = 3.

  • An overdraft of £5 plus a deposit of £8 results in a balance of £3.