Adding and subtracting
Add and subtract whole numbers, and see that subtraction undoes addition.
Planned. This module is part of the plan and is not written yet.
Why it matters
Ama sells 35 oranges in the morning and 27 in the afternoon: adding tells her how many she sold today, and subtracting tells her how many are left in the basket.
Draft outline · in review- For
- Level 1–3 · Primary 1 to Primary 3
- Inside
- 5 lessons and a test · about 60 minutes
- Topic
- Operations · foundation, 1 of 4
Inside the module.
5 lessons in order, about 60 minutes in all, then a short test. Learners go at their own pace; the minutes are a guide, not a timetable.
Draft outline · in review
Lesson 1: Counting on and back
Use a number line and bottle tops to add by counting on and subtract by counting back.
Explain12 min, from minute 0
Lesson 2: Tens and ones
Add and subtract two-digit numbers by working with the tens and the ones.
Worked example15 min, from minute 12
Lesson 3: Fact families
See how 7 + 5 = 12 also gives 5 + 7 = 12, 12 − 5 = 7 and 12 − 7 = 5.
Explain10 min, from minute 27
Lesson 4: Market stall stories
Solve short buying and selling stories with numbers up to 100.
Practice15 min, from minute 37
Lesson 5: Review
Mixed adding and subtracting questions, with feedback on each.
Review8 min, from minute 52
End-of-module test
Add and subtract numbers up to 100, including in short stories, and complete fact families.
Mastered at 85% or more. Retake it until you pass; nothing is lost, and each try gives feedback.
Already know it? A Challenge Test (planned) clears the whole module: 90% overall, no objective below 75%.
Last stageafter about 60 min
Practicalities
Draft outline · in reviewBuilt to run offline
Planned to run on the Lantern's own computer, with no internet needed.
Languages
Planned first in English; every module aims to reach all of the Lantern's languages.
Try a question.
One question from the module, as a learner would meet it. Have a go, then open the worked solution a step at a time.
Draft outline · in review
Kofi knows that 8 + 6 = 14. Which subtraction fact can he find from it without counting?
Particulars
Where it sits
What a learner can do after it
- Add and subtract numbers up to 100.
- Use one fact to find another: 7 + 5 = 12, so 12 − 5 = 7.
Needs first
This module has no prerequisites of its own. Like every first step, it assumes the Digital skills gateway: the first module on using a computer, which a Challenge Test clears in minutes.
Level
Level 1–3 · Primary 1 to Primary 3
Level mappings are approximate. A qualified teacher or lecturer in each country must check them before they appear in the app.
Difficulty for its level
1 of 4 · Foundation
Time
About 60 minutes
Alignments
None drafted yet.
Alignment in review until a qualified teacher or lecturer checks it. No exam body, university or vendor endorses us; learners still sit the real exam.
Challenge Test
Planned: a Challenge Test to prove you know it and skip it. Pass at 90% overall, with no objective below 75%.
The route here.
Everything this module builds on, drawn as a route from its foundations. Solid lanes must be mastered first, or cleared by a Challenge Test; dashed lanes are suggestions that never lock anything.
This module has no prerequisites of its own. Like every first step, it assumes the Digital skills gateway: the first module on using a computer, which a Challenge Test clears in minutes.
Help light the room where this is learned.
Every route on this map starts in a classroom with 24 stations, a tutor that works offline and a facilitator upstairs. Four are planned and waiting for light.