Checkpoint Vault Breakout

See Page 2 for Sectors 3 & 4 Solutions, Passcode Terminal, and Misconception Guide.

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Teacher Guide: Sectors 3 & 4 Solutions & Remediation

ILEARN CHECKPOINT 1 KEY

3

Sector 3 Solutions: The Computation Chamber

LOCK 3 DIGIT = 8

Q7. Addition Algorithm KEY: 482

\(5 + 7 = 12\) (regroup 1 ten). \(1 + 4 + 3 = \mathbf{8}\) tens. \(3 + 1 = 4\) hundreds. Sum = \(\mathbf{482}\).

Check for error: Forgetting to add regrouped 1 yields 472.

Q8. Regrouping Subtraction KEY: 266

\(624 - 358 = \mathbf{266}\). Ones: regroup 1 ten \(\rightarrow 14 - 8 = 6\). Tens: regroup 1 hundred \(\rightarrow 11 - 5 = 6\). Hundreds: \(5 - 3 = 2\).

Notice double regrouping required across tens and hundreds.

Q9. Two-Step Problem KEY: B

Step 1: \(180 - 45 = 135\). Step 2: \(135 + 25 = \mathbf{160}\) stickers.

Distractor analysis: Option A only subtracts \(45 + 25 = 70\); C adds both \(45 + 25\).

Lock 3 Cipher Explanation: The tens digit of 482 (from Q7) is 8. Recorded Code: [ 8 ]

4

Sector 4 Solutions: Array & Operations Arena

LOCK 4 DIGIT = 3

Q10. Array Equation KEY: B

The array has 3 rows with 5 dots in each row: \(3 \times 5 = \mathbf{15}\).

Option A confuses addition with multiplication (\(3 + 5 = 8\)).

Q11. Equal Groups Word Problem KEY: 24 apples

4 baskets of 6 apples = \(4 \times 6 = \mathbf{24}\) apples in all (or \(6 + 6 + 6 + 6 = 24\)).

Check that students don't write \(4 + 6 = 10\).

Q12. Multiplication Situation KEY: B

3 packs of 7 pens represents 3 equal groups of 7, solved by \(3 \times 7 = \mathbf{21}\).

A is an addition context (\(3 + 7\)); C is subtraction (\(7 - 3\)).

Lock 4 Cipher Explanation: The array in Q10 has 3 horizontal rows. Recorded Code: [ 3 ]

Master Vault Code Solution

4

6

8

3

DECODED WORD: M • A • T • H

If a student gets an incorrect letter, use the lock number to immediately identify which math sector needs review!

Targeted Checkpoint 1 Intervention Guide

• Lock 1 incorrect (Place Value): Reinforce expanded notation using base-ten blocks. Review that the position of a digit determines its value (e.g., 4 thousands = 4,000, not 4).
• Lock 2 incorrect (Rounding): Have students draw a vertical or horizontal number line and identify the midpoint (e.g., 65 between 60 and 70). Emphasize benchmark numbers.
• Lock 3 incorrect (Computation): Scaffold regrouping steps with place value charts. Check whether students remember to add the regrouped ten in multi-digit addition.
• Lock 4 incorrect (Multiplication): Practice circling equal groups and building arrays with counters before writing equations (\(\text{rows} \times \text{columns} = \text{total}\)).

Ready for classroom print, independent checkpoint prep, and math centers.

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