Number patterns and unknown quantities
"Let's think it through," says Ollie. "A missing number is just a number in hiding — use what you know to find it."
1. Find the number under the leaf.
a) 25 + □ = 40 □ = b) □ − 12 = 30 □ =
c) 60 − □ = 45 □ =
2. Continue each pattern and write the rule.
a) 3, 6, 9, 12, , Rule:
b) 5, 10, 15, 20, , Rule:
3. Write a different number sentence equal to 12 + 8.
4. True or false? 15 + 5 = 12 + 8. Explain.
5. Challenge: Pip's star pattern is 2, 4, 8, 16, … What is the rule, and what comes next?