Add & Sub 2
Overview
Add & Sub 2 introduces students to addition and subtraction with larger numbers, reinforcing number bonds and arithmetic fluency. Questions include sums and differences such as 1 + 15, 21 + 2, 12 − 5, and 18 − 8. Learners practise solving both types of operations, ensuring they can switch flexibly between adding and subtracting. The visual layout presents the equation with a missing answer, and students select the correct option from two choices. This Phlow builds confidence with numbers beyond 10 and strengthens accuracy in mental maths.
Prerequisite Knowledge Required
- Understanding of single-digit addition and subtraction (see Add 1, Subtract 1)
- Familiarity with number sequences up to 20
Main Category
Arithmetic
Estimated Completion Time
Approx 6-10 seconds per question. 20 questions total. Total time: 2-4 minute.
Cognitive Load / Step Size
Moderate — introduces slightly larger numbers while keeping one-step operations consistent. Step size is well balanced to reinforce fluency without overwhelming the learner.
Language & Literacy Demand
Minimal — clear symbols and short phrasing; visual numbers support comprehension.
Clarity & Design
Clean layout with strong contrast; equations are central with clear choice buttons. Visual simplicity aids focus and mental calculation.
Curriculum Alignment
Aligned with Number – Operations (Addition and Subtraction): perform addition and subtraction within 20, demonstrating understanding of number bonds.
Engagement & Motivation
Fast-paced and rewarding for learners mastering early arithmetic; immediate feedback keeps attention high.
Error Opportunities & Misconceptions
- Students may mix up addition and subtraction.
- Overlooking carrying/borrowing when transitioning to larger numbers.
Transferability / Real-World Anchoring
Supports everyday mental maths, such as counting money or combining quantities.
Conceptual vs Procedural Balance
Primarily procedural — focused on fluent recall and accurate calculation, reinforcing earlier conceptual understanding.
Learning Objectives Addressed
- Apply addition and subtraction to numbers beyond 10.
- Strengthen number bond recognition.
- Develop mental calculation speed and accuracy.
- Distinguish between adding and subtracting in context.
What Your Score Says About You
- Less than 5: Still developing fluency — revisit earlier Phlows like Add 1 or Subtract 1.
- Between 6–7: Good progress — building consistency with larger numbers.
- Between 8–9: Strong fluency — nearly automatic recall of number facts.
- 10/10: Excellent accuracy and mental flexibility with both operations.