Maths- Year End Review

Maths- Year End Review

Review everything taught in chapters 1 and 2.

Introduction

Maths is a broad and complex subject. Some parts are as easy as taking a nap, but others can keep you on edge! Today, we'll be scratching the surface of this ocean of concepts. So hop in as we lift off to take a look at the basics!

Chapter 1

Whole numbers up to the millions

Agenda

• Chapter 1:

• What Counts?

• Place Values and Face Values

• Addition and subtraction

• Estimation

• Rounding

• Chapter End Assessment

What counts?

When we think of numbers, we usually think of whole numbers, such as 1, 2, 3 and so on. All maths, be it simple addition or the complex exponentiation, is just a form of glorified counting! Each number is unique and has a unique order of digits. Each digit corresponds to a place of the whole number each with a different spot in it. This is the digit's place value of the number. The value of the digit 2 in 123 is different from the value of 2 in 213 i.e 20 and 200 respectivly.

ABOVE IS A PLACE VALUE CHART. THEY ARE USEFUL TO DIFFERENTIATE PLACE VALUES FROM FACE VALUES.

A company has $5,342,412 in a bank. Then, it deposits another $546,539 in it. How much does it have?

• Add and regroup the ones to get 11; which is 1.

• Then, add the tens; 51.

• Next, add the hundrends; 951.

• After that, add the thousands; 8,951

• Then, add the ten thousands; 88,951

• Next, add the hundrend thousands; 888, 951.

• Last, add the millions; 5,888,951. The answer is $5,888,951.

Rounding

Numbers, especially large ones, are hard to crunch. This is why we use estimation. Estimation is when you take an educated guess that is relatively close to the actual answer. The most common type of estimation is rounding, where you take a look at the digit just right of the place value you are rounding, and determine weather if it's rounded up or down. Usually, numbers 4 and lower are rounded to 0, while the numbers 5 and up are rounded up to 10.

125,376 is closer to 100,000 than to 200,000.

Multiple Choice

Dan has 5,000 worksheets. He distributes them to 100 students with each getting 30 worksheets. How much does he have left?

• 20

• 2,000

• 10,000

• 100

Multiple Choice

Bhavan has $1,000,000 in his bank account. He bought a few cars worth $249,999 in total. How much does he have left? Round your answer to the nearest ten thousand.

• $750,000

• $750,001

• $75,000

• None of these

Multiple Select

What answer(s) can be rounded to 10,000?

• 12,563

• 6,572

• 120,831

• 649

Chapter 2

Whole numbers multiplication and division

Agenda

• Chapter 2:

• Think, think, think!

• Multiplication

• A whole lotta cookies!

• Division

• Decimalia

• Chapter End Assessment

Think, think, think!

What are we thinking about? Nothing! We're just repeating the same thought again and again and again, just like multiplication and division! If there were 5 students and each had 5 pencils, you don't need to add five to five five times! All you do is multiply 5x5=25! The same goes for division. If there were 5 students each having the same number of pencils with a total of 25, you can divide 25÷5=5!

Always multiply from right to left so that you don't miss groups!

A baker makes 31 batches of cookies a week. Each batch has 28 cookies in it. How many more cookies are made in a year than in a week?

• First multiply 31 and 28 to get the number of cookies per week which is 868.

• Divide that by 7 for every day in a week to get 124.

• Multiply that with 365 days of the year to get 316,820 cookies.

• Subtract that with 868 to get the final answer which is 315,952.

Division

Which is more straight forword; 20-5-5-5, or 20÷4? Division means repeated subtraction. A similar thing happens when you cut a pizza; you "divide" it into sections- also known as slices. Division is the most confusing out of the 4 major mathamatical operations, so mastering it is a must. Without anymore chatting, let's divide!

Without dealing with decimals, we can reach an answer of 1277 R2. If you really fancy decimals, the answer is 1277.5.

Multiple Choice

What is the least common multiple of 12 and 18?

• 36

• 48

• 12

• 24

Multiple Choice

Find the formula for the given question:

Multiply the quotient 50 by 2 with 10.

• $\frac{5\cdot2}{10}$

• $\frac{50}{10\cdot2}$

• $\frac{50}{2}\cdot10$

• None of these

Multiple Select

Select all that are multiples of 7.

• 42

• 36

• 17

• 56

The End!

You are now done with your lesson