Purpose
These exercises and activities are for students to use independently of the teacher to practise number properties.
Achievement Objectives
NA4-1: Use a range of multiplicative strategies when operating on whole numbers.
Specific Learning Outcomes
use common factors to help solve addition and subtraction problems
Description of Mathematics
Addition and Subtraction, AM (Stage 7)
Required Resource Materials
Homework with answers (PDF or Word)
Practice exercises with answers (PDF or Word)
Activity
Prior knowledge
Recall multiplication basic facts
Know factors
Familiarisation with the use of brackets in notation
Multiply two digit numbers by a single digit number using the distributive law
eg 15 x 6 = (10 x 6) + (5 x 6) = 90
eg 15 x 6 = (10 x 6) + (5 x 6) = 90
Background
The strategy in this activity involves finding a common factor of numbers in an addition problem. For example, 27 + 45 a common factor of 27 and 45 is 9. So 27 + 45 = (3 x 9) + (5 x 9). Then by using the distributive property the equation can be rearranged as 27 + 45 = (3 x 9) + (5 x 9) = 8 x 9 = 72.
Comments on the Exercises
Exercise 1
Asks students to solve addition problems using common factors and the distributive law.
Asks students to solve addition problems using common factors and the distributive law.
Exercise 2
Asks students to decide if problems have correctly been solved using common facts and the the distributive law.
Attachments
MultipleWaysSheet.pdf91.71 KB
MultipleWaysSheet.doc46.5 KB
MultipleWaysHW.pdf88.52 KB
MultipleWaysHW.doc45 KB
MultipleWaysLoopy.pdf76.38 KB
MultipleWaysLoopy.doc48.5 KB
LoopyMaster.doc44.5 KB
Add to plan
Level Four