Arithmetic Expressions

Question 4

  1. In each of the sets of expressions below, identify those that have the same value. Do not evaluate them, but rather use your understanding of terms.

(a) 319+537319 + 537, 319537319 - 537, 537+319-537 + 319, 537319537 - 319

(b) 87+4610987 + 46 - 109, 87+4610987 + 46 - 109, 87+4610987 + 46 - 109, 8746+10987 - 46 + 109, 87(46+109)87 - (46 + 109), (8746)+109(87 - 46) + 109

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Solution

We find expressions with the same value. We check numbers and their signs.

Step 1 — Comparing expressions in set (a)

Let us write down each expression. We will identify the numbers and their signs.

The first expression is 319+537319 + 537. 319+537319 + 537 This means we add 319 and 537.

The second expression is 319537319 - 537. 319537319 - 537 Subtracting 537 is the same as adding -537. So, this expression is 319+(537)319 + (-537).

The third expression is 537+319-537 + 319. 537+319-537 + 319 The order of adding numbers does not change the sum. So, this is the same as 319+(537)319 + (-537).

The fourth expression is 537319537 - 319. 537319537 - 319 Subtracting 319 is the same as adding -319. So, this expression is 537+(319)537 + (-319).

Now we compare them. These expressions involve adding 319 and -537. They have the same numbers with the same signs.

The expressions 319 - 537 and -537 + 319 have the same value.\boxed{\text{The expressions 319 - 537 and -537 + 319 have the same value.}}

Diagram 1

Step 2 — Comparing expressions in set (b)

Let us write down each expression. We will identify the numbers and their signs.

The first expression is 87+4610987 + 46 - 109. 87+4610987 + 46 - 109 This means we add 87 and 46. Then we subtract 109.

The second expression is 87+4610987 + 46 - 109. 87+4610987 + 46 - 109 This expression is exactly the same as the first one.

The third expression is 87+4610987 + 46 - 109. 87+4610987 + 46 - 109 This expression is also exactly the same as the first one.

The fourth expression is 8746+10987 - 46 + 109. 8746+10987 - 46 + 109 This means we subtract 46 from 87. Then we add 109.

The fifth expression is 87(46+109)87 - (46 + 109). 87(46+109)87 - (46 + 109) When we have brackets, we do the operation inside first. So, we add 46 and 109. Then we subtract this sum from 87. This is different from the other expressions. Subtracting a sum is like subtracting each number. So, this is 874610987 - 46 - 109.

The sixth expression is (8746)+109(87 - 46) + 109. (8746)+109(87 - 46) + 109 Here, we first subtract 46 from 87. Then we add 109 to the result. This is the same as 8746+10987 - 46 + 109. The brackets just make the order clear.

Now we compare them. The expressions 87+4610987 + 46 - 109 (all three instances) are identical.

The expressions 87 + 46 - 109 (all three instances) have the same value.\boxed{\text{The expressions 87 + 46 - 109 (all three instances) have the same value.}} The expressions 87 - 46 + 109 and (87 - 46) + 109 have the same value.\boxed{\text{The expressions 87 - 46 + 109 and (87 - 46) + 109 have the same value.}}

Answer

(a) 319537319 - 537 and 537+319-537 + 319 have the same value. (b) 87+4610987 + 46 - 109, 87+4610987 + 46 - 109, and 87+4610987 + 46 - 109 have the same value. Also, 8746+10987 - 46 + 109 and (8746)+109(87 - 46) + 109 have the same value.

More questions in this chapter

Q1

Figure it Out

  1. Fill in the blanks with numbers, and boxes with operation signs such that the expressions on both sides are equal.

    (a) 24+(64)=24+6  24 + (6 - 4) = 24 + 6 \ \square \ \underline{\quad}

    (b) 38+(  )=38+9438 + (\underline{\quad} \ \square \ \underline{\quad}) = 38 + 9 - 4

    (c) 24(6+4)=24  6424 - (6 + 4) = 24 \ \square \ 6 - 4

    (d) 2464=246  24 - 6 - 4 = 24 - 6 \ \square \ \underline{\quad}

    (e) 27(8+3)=27  8  327 - (8 + 3) = 27 \ \square \ 8 \ \square \ 3

    (f) 27(  )=278+327 - (\underline{\quad} \ \square \ \underline{\quad}) = 27 - 8 + 3

Q2
  1. Remove the brackets and write the expression having the same value.

(a) 14+(12+10)14 + (12 + 10)

(b) 14(12+10)14 - (12 + 10)

(c) 14+(1210)14 + (12 - 10)

(d) 14(1210)14 - (12 - 10)

(e) 14+(1210)-14 + (12 - 10)

(f) 14(1210)14 - (-12 - 10)

Q3
  1. Find the values of the following expressions. For each pair, first try to guess whether they have the same value. When are the two expressions equal?

(a) (6+10)2(6 + 10) - 2 and 6+(102)6 + (10 - 2)

(b) 16(83)16 - (8 - 3) and (168)3(16 - 8) - 3

(c) 27(18+4)27 - (18 + 4) and 27+(184)27 + (-18 - 4)

Q4
  1. In each of the sets of expressions below, identify those that have the same value. Do not evaluate them, but rather use your understanding of terms.

(a) 319+537319 + 537, 319537319 - 537, 537+319-537 + 319, 537319537 - 319

(b) 87+4610987 + 46 - 109, 87+4610987 + 46 - 109, 87+4610987 + 46 - 109, 8746+10987 - 46 + 109, 87(46+109)87 - (46 + 109), (8746)+109(87 - 46) + 109

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