LEARN · PRACTISE · DISCOVER

Mental Math Challenge Project

Read at your own pace. Try the practice, then continue your course.

Use estimation, number bonds, mental strategies, and a model to solve a real-world challenge and explain your answer.

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THE CURIOSI · EXPLORE & TRY

Explore the model, then test your understanding. Select each numbered stop to discover its role.

Strategy model: follow the labelled quantities and explain each change. Number-line jumps are schematic.

1Estimate first

About 100 cards minus about 30 and 40 suggests about 30 remain.

2Combine the table groups

28 + 35 = 63 cards on the two tables.

3Find and check the remainder

96 − 63 = 33 cards remain. Check 28 + 35 + 33 = 96.

Choose a strategy you can explain. Check the numbers and include units where needed.

Choose one answer for each question, then check. Practice results stay on this page and do not change course completion.

1. How many cards are on the tables? 33 61 63

2. How many cards remain in the box? 159 33 63

3. Which check accounts for every card? 28 + 35 + 33 = 96 28 + 35 = 33 96 + 63 = 33

Read the answer explanations

Focus on understanding before speed. Use paper, counters or a spoken explanation whenever they help you keep track.