Lesson Notes By Weeks and Term v4 - JHS 1
Number and Numeration Systems
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Number and Numeration Systems
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Subject: Mathematics
Class: JHS 1
Term: 1st Term
Week: 4
Grade code: B7.1.1.1.5
Strand code: 4
Sub-strand code: 1
Content standard code: B7.1.1.1
Indicator code: B7.1.1.1.5
Theme: HANDLING DATA ...................................................................................................................................................................................................................................................................... 211
Subtheme: Number and Numeration Systems
This page supports the lesson note with a companion video and a short classroom-ready summary.
For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.
In our daily lives in Ghana, we often deal with numbers that are more precise than we need. For example, when we calculate the cost of items in a market, measure ingredients for a recipe, or read about national statistics, we often simplify these numbers to make them easier to understand and use. This process of simplifying numbers is called rounding or approximation. This lesson will teach you two important ways to round decimal numbers: to a specific number of decimal places and to a specific number of significant figures. Mastering this skill is essential for accuracy in calculations in mathematics, science, and everyday financial transactions.
This lesson is divided into two main parts: rounding to Decimal Places and rounding to Significant Figures. Part 1: Rounding to Decimal Places (d.p.)
What are Decimal Places? Decimal places refer to the number of digits that come *after* the decimal point in a number. Example: In the number 34.725, `7` is in the first decimal place. `2` is in the second decimal place. `5` is in the third decimal place. This number has 3 decimal places.
The Rule for Rounding: To round a number, we look at the digit immediately to the right of the place we are rounding to. This is our "decider" digit. If the decider digit is 5 or more (5, 6, 7, 8, or 9), we "round up". This means we add 1 to the previous digit (the rounding digit). If the decider digit is less than 5 (0, 1, 2, 3, or 4), we "round down". This means we leave the previous digit as it is. After rounding, we drop all the digits that come after the rounding place.