- Home
- Canvas Guide
Partial Progress - Circles (browser only)
Time - Addition & Subtraction
Objectives
To be able to add and subtract with time using the Frog method.
To remember that there are 60 minutes in one hour.
Resources
Abacus 4 Textbook 2 | Squared paper
Today's Lesson
Main Activity
For mental warm ups, ask your student to count up and back in 5s and 10s from a number that is not a multiple of 10. For example: Count on in 5s from 8. Count back in 10s from 56.
Look at the example at the top of page 73 in Abacus 4 Textbook 2.
Explain to your student that the Frog method of addition and subtraction can be used for calculations involving time, as well. Remind your student that there are 60 minutes in one hour, not 100. Discuss the diagram and ensure that your student has understood how they can use the Frog method here.
Watch 'Durations of Time' for some examples of time problems.
Ask your student to read the problems on the page aloud and to tell you what they think is being asked. Once you are happy that your student understands, encourage them to work independently, using Frog to complete the work.
If necessary, allow your student to draw the number lines to help. Remind them to include the unit of measure and to write a sentence answer, as well as the calculation.