First write each expression as a sum of terms, evaluate each term, then add.
| As a sum of terms | Terms | Value | |
|---|---|---|---|
| (a) | 28 + (–7) + 8 | 28, –7, 8 | 29 |
| (b) | 39 + (–2 × 6) + 11 | 39, –2 × 6, 11 | 38 |
| (c) | 40 + (–10) + 10 + 10 | 40, –10, 10, 10 | 50 |
| (d) | 48 + (–10 × 2) + (16 ÷ 2) | 48, –10 × 2, 16 ÷ 2 | 36 |
| (e) | (6 × 3) + (–4 × 8 × 5) | 6 × 3, –4 × 8 × 5 | –142 |
(b) –2 × 6 = –12, so 39 + (–12) + 11 = 27 + 11 = 38
(c) 40 + (–10) + 10 + 10 = 30 + 10 + 10 = 50
(d) –10 × 2 = –20 and 16 ÷ 2 = 8, so 48 + (–20) + 8 = 28 + 8 = 36
(e) 6 × 3 = 18 and 4 × 8 × 5 = 160, so 18 + (–160) = –142