Given, 23 × 10 2 We know that, if a × 10 7 (where a is a number), then to multiply a by 10 7 , move the digit ' a ' seven places to the left in the place value table and fill seven empty spaces with zeros. So, a × 10 7 = a × 10000000 Or, if any positive whole number is a power of 10 multiplied by any number, then we have to add the same number of zeros equals to the power of 10 to the end of the given number. In this question, move the digits 2 and 3 , two places to the left in the place value table. And fill two empty spaces with zeros. Or add two zeros to the end of 23 . Hence, 23 × 10 2 = 23 × 100 = 2300 .

Work out: 768 × 10 4

Given, 768 × 10 4 We know that, if a × 10 7 (where a is a number), then to multiply a by 10 7 , move the number ' a ' seven places to the left in the place value table and fill seven empty spaces with zeros. So, a × 10 7 = a × 10000000 Or, if any positive whole number is a power of 10 multiplied by any number, then we have to add the same number of zeros equals to the power of 10 to the end of the given number. In this question, move the digits 7 , 6 and 8 , four places to the left in the place value table. And fill four empty spaces with zeros. Or add four zeros to the end of 768 . Hence, 768 × 10 4 = 768 × 10000 = 7680000 .

Given, 9 × 10 6 We know that, if a × 10 7 (where a is a number), then to multiply a by 10 7 , move the number ' a ' seven places to the left in the place value table and fill seven empty spaces with zeros. So, a × 10 7 = a × 10000000 Or, if any positive whole number is a power of 10 multiplied by any number, then we have to add the same number of zeros equals to the power of 10 to the end of the given number. In this question, move the digit 9 , six places to the left in the place value table. And fill six empty spaces with zeros. Or add six zeros to the end of 9 . Hence, 9 × 10 6 = 9 × 1000000 = 9000000 .

Classify these number cards into groups of the same value. There should be one number left over. 7 . 8 × 10 3 7800000000 ÷ 10 7 0 . 0078 × 10 4 780 × 10 780 ÷ 10 78000000 ÷ 10 4 78 × 10 0 . 00078 × 10 6 780 ÷ 10 2 78000 ÷ 10 3

We have to classify the given cards into groups of the same value. So, we will simplify each of the given expression. Now, 7 . 8 × 10 3 There are 3 zeroes in 10 3 , so we move the decimal point three places to the right. If there are any empty spaces, we fill them with zeroes. So, 7 . 8 × 10 3 = 7800 Similarly, 0 . 0078 × 10 4 = 78 780 × 10 = 7800 78 × 10 = 780 0 . 00078 × 10 6 = 780 Again, 7800000000 ÷ 10 7 There are 7 zeroes in 10 7 , so we move the decimal point three places to the left. If there are any empty spaces, we fill them with zeroes. So, 7800000000 ÷ 10 7 = 780 Similarly, 780 ÷ 10 = 78 78000000 ÷ 10 4 = 7800 780 ÷ 10 2 = 7 . 8 78000 ÷ 10 3 = 78 Therefore, the results are 7 . 8 , 78 , 780 and 7800 . We will classify the given cards into these groups: 7 . 8 78 780 7800 780 ÷ 10 2 0 . 0078 × 10 4 780 ÷ 10 78000 ÷ 10 3 78 × 10 0 . 00078 × 10 6 7800000000 ÷ 10 7 7 . 8 × 10 3 780 × 10 78000000 ÷ 10 4 We can see that there are three groups each having three cards and one card 780 ÷ 10 2 is left.

E M B I B E

Cambridge Lower Secondary Mathematics Learner's Book 7 Second Edition Digital Access>Chapter 3 - Place Value and Rounding>Exercise 3.1

Lynn Byrd, Greg Byrd and, Chris Pearce Solutions for Chapter: Place Value and Rounding, Exercise 2: Exercise 3.1

Author:Lynn Byrd, Greg Byrd & Chris Pearce

Lynn Byrd Mathematics Solutions for Exercise - Lynn Byrd, Greg Byrd and, Chris Pearce Solutions for Chapter: Place Value and Rounding, Exercise 2: Exercise 3.1

Attempt the practice questions on Chapter 3: Place Value and Rounding, Exercise 2: Exercise 3.1 with hints and solutions to strengthen your understanding. Cambridge Lower Secondary Mathematics Learner's Book 7 Second Edition Digital Access solutions are prepared by Experienced Embibe Experts.

Questions from Lynn Byrd, Greg Byrd and, Chris Pearce Solutions for Chapter: Place Value and Rounding, Exercise 2: Exercise 3.1 with Hints & Solutions

EASY

Lower Secondary Stage 7

IMPORTANT

Cambridge Lower Secondary Mathematics Learner's Book 7 Second Edition Digital Access>Chapter 3 - Place Value and Rounding>Exercise 3.1>Q 4

Marcus says: 'When I multiply a whole number by $10^{4}$ , I just have to add four zeros to the end of the number. When I multiply a whole number by $10^{5}$ , I just have to add five zeros to the end or the number. This works for any positive whole number power of ten.' Is Marcus correct?