This is the marking copy and it carries every answer. Her sheet is the other file — same numbering, same margin codes, so you can mark straight down the page.
Andy bought 4 identical shirts at $12.80 each and spent the rest of the money on 8 identical pairs of socks. He gave $100 to the cashier and received 80 cents change. How much did each pair of socks cost?
answer 6
method He spent $100 − $0.80 = $99.20 in total. The shirts cost 4 × $12.80 = $51.20, so the socks cost $99.20 − $51.20 = $48. There are 8 pairs, so each pair is $48 ÷ 8 = $6.
watch Treating 80 cents as $80, or forgetting to take the change off the $100 before splitting the rest.
Round the sum of 18.208 and 1.42 to the nearest whole number.
answer 20
method Add first, lining up the decimal points: 18.208 + 1.420 = 19.628. Then round to the nearest whole number — the digit after the point is 6, which is 5 or more, so round up to 20.
watch Rounding each number first (18 + 1 = 19). The question says round the SUM, and rounding early loses the 0.628 that pushes it over.
Zainal had 5 m of ribbon at first. He used 1.4 m of it to wrap a present and some ribbon to decorate 2 cards. He had 2.6 m of ribbon left. Which of the following is the length of ribbon for each card?
(1) 1 m (2) 2 m (3) 0.7 m (4) 0.5 m
answer (4) — 0.5 m
method Find the ribbon used on the cards: 5 − 1.4 − 2.6 = 1 m for BOTH cards. Then share it: 1 ÷ 2 = 0.5 m for each card.
watch Stopping at 1 m — that is the ribbon for two cards, and the question asks for each one.