Work through the levels in order. Type your answer and press Check — open the worked solution if you get stuck. Answers like -6, 3/4 or 0.25 are typed exactly as shown. A ⭐ Bonus Challenge at the end is extra credit — skip it if the rest was hard work.
Level 1 · Warm-up
1 Work out 3.6 + 2.75.
Show worked solution
3.60 + 2.75 = 6.35.
2 What is $5.00 − $3.45? Give the dollars and the cents.
Show worked solution
5.00 − 3.45 = 1.55: 1 dollar and 55 cents.
3 Add 0.75 and 1.5.
Show worked solution
1.50 + 0.75 = 2.25.
Level 2 · Core
4 Three parcels have masses 2.05 kg, 0.9 kg and 1.35 kg. What is their total mass?
Show worked solution
2.05 + 0.90 + 1.35 = 4.3 kg. (13.4 is from lining up the last digits.)
5 For 12.5 − 4.85, give an estimate using whole numbers and the exact answer.
Show worked solution
Estimate: 13 − 5 = 8. Exact: 12.50 − 4.85 = 7.65.
6 A city grew from 4.85 million to 6.2 million. By how many million did it grow?
Show worked solution
6.20 − 4.85 = 1.35 million.
Level 3 · Challenge
7 A receipt lists $12.95, $3.50 and $0.85, paid with a $20 note.1 The total is $17.30.
2 The change from $20 is $2.70.
3 Rounding each item to the nearest dollar gives an estimate of $18.
Which statements are correct?
2 The change from $20 is $2.70.
3 Rounding each item to the nearest dollar gives an estimate of $18.
Which statements are correct?
Show worked solution
12.95 + 3.50 + 0.85 = 17.30 (1 ✓). 20.00 − 17.30 = 2.70 (2 ✓). 13 + 4 + 1 = 18 (3 ✓). 1, 2 and 3.
8 A plank is 3 m long. Two pieces are cut off: 0.85 m and 1.4 m. How much plank is left, and by how much is the longer offcut longer than the shorter?
Show worked solution
3.00 − 0.85 = 2.15; 2.15 − 1.40 = 0.75 m left. 1.40 − 0.85 = 0.55 m.
9 Kai spends $12.85, then receives $20, and now has $31.60. How much, in dollars, did he have to begin with?
Show worked solution
31.60 − 20.00 = 11.60. Then add the spending back: 11.60 + 12.85 = $24.45.