練習問題
1章 正の数と負の数
2.正の数・負の数の加法と減法
※問題の解答を非表示にする場合は、このボタンを押してください。
(問1)
(1) (−4)+6
(2) (−6)+3
(3) (−8)+7
(4) (−12)+16
(5) (−20)+9
(6) (−23)+23
(7) −3+21
(8) −33+19
(1) (−4)+6
(2) (−6)+3
(3) (−8)+7
(4) (−12)+16
(5) (−20)+9
(6) (−23)+23
(7) −3+21
(8) −33+19
(1) (−4)+6=2
(2) (−6)+3=−3
(3) (−8)+7=−1
(4) (−12)+16=4
(5) (−20)+9=−11
(6) (−23)+23=0
(7) −3+21=18
(8) −33+19=−12
(問2)
(1) (+3)−9
(2) 6−8
(3) 4−11
(4) (−4)−2
(5) (−7)−9
(6) −14−9
(7) 27−44
(8) −36−58
(1) (+3)−9
(2) 6−8
(3) 4−11
(4) (−4)−2
(5) (−7)−9
(6) −14−9
(7) 27−44
(8) −36−58
(1) (+3)−9=−6
(2) 6−8=−2
(3) 4−11=−7
(4) (−4)−2=−6
(5) (−7)−9=−16
(6) −14−9=−23
(7) 27−44=−17
(8) −36−58=−94
(問3)
(1) 8+(−5)
(2) (−7)+(−1)
(3) (+6)+(−6)
(4) (−3)+(−9)
(5) 6+(−24)
(6) (+15)+(−26)
(7) −10+(−19)
(8) −39+(−39)
(1) 8+(−5)
(2) (−7)+(−1)
(3) (+6)+(−6)
(4) (−3)+(−9)
(5) 6+(−24)
(6) (+15)+(−26)
(7) −10+(−19)
(8) −39+(−39)
(1) 8+(−5)=3
(2) (−7)+(−1)=−8
(3) (+6)+(−6)=0
(4) (−3)+(−9)=−12
(5) 6+(−24)=−18
(6) (+15)+(−26)=−9
(7) −10+(−19)=−29
(8) −39+(−39)=−78
(問4)
(1) 6−(−3)
(2) 8−(−6)
(3) 0−(−2)
(4) (−7)−(−9)
(5) (−5)−(−5)
(6) (−25)−(−42)
(7) −21−(−39)
(8) −44−(−28)
(1) 6−(−3)
(2) 8−(−6)
(3) 0−(−2)
(4) (−7)−(−9)
(5) (−5)−(−5)
(6) (−25)−(−42)
(7) −21−(−39)
(8) −44−(−28)
(1) 6−(−3)=9
(2) 8−(−6)=14
(3) 0−(−2)=2
(4) (−6)−(−9)=3
(5) (−5)−(−5)=0
(6) (−25)−(−42)=17
(7) −21−(−39)=18
(8) −44−(−28)=−16
(問5)
(1) 5−3+8−2
(2) 13−8+6−9
(3) (+5)+(−6)−(+7)
(4) (−7)−(−2)+(−9)
(5) −15+(−8)−(−7)
(6) −24−(−18)−12
(7) −47+(−25)+(−14)+11
(8) (−36)+24+(+61)−(+31)
(1) 5−3+8−2
(2) 13−8+6−9
(3) (+5)+(−6)−(+7)
(4) (−7)−(−2)+(−9)
(5) −15+(−8)−(−7)
(6) −24−(−18)−12
(7) −47+(−25)+(−14)+11
(8) (−36)+24+(+61)−(+31)
(1) 5−3+8−2
=13−5
=8
(2) 13−8+6−9
=19−17
=2
(3) (+5)+(−6)−(+7)
=5−6−7
=5−13
=−8
(4) (−7)−(−2)+(−9)
=−7+2−9
=−16+2
=−14
(5) −15+(−8)−(−7)
=−15−8+7
=−23+7
=−16
(6) −24−(−18)−12
=−24+18−12
=−36+18
=−18
(7) −47+(−25)+(−14)+11
=−47−25−14+11
=−86+11
=−75
(8) (−36)+24+(+61)−(+31)
=−36+24+61−31
=−67+85
=18
(問6)
(1) −9+2.8
(2) (−3.8)−8.5
(3) (+4.7)+(−7.3)
(4) −6.2−(−5.5)
(5) −6.84+(−2.8)
(6) 12.56−(−3.14)
(7) 0.5+(−4.8)−7.9
(8) 0.8−4.2+8.3−(−2.8)
(1) −9+2.8
(2) (−3.8)−8.5
(3) (+4.7)+(−7.3)
(4) −6.2−(−5.5)
(5) −6.84+(−2.8)
(6) 12.56−(−3.14)
(7) 0.5+(−4.8)−7.9
(8) 0.8−4.2+8.3−(−2.8)
(1) −9+2.8=−6.2
(2) (−3.8)−8.5
=−3.8−8.5
=−12.3
(3) (+4.7)+(−7.3)
=+4.7−7.3
=−2.6
(4) −6.2−(−5.5)
=−6.2+5.5
=−0.7
(5) −6.84+(−2.8)
=−6.84−2.8
=−9.64
(6) 12.56−(−3.14)
=12.56+3.14
=15.7
(7) 0.5+(−4.8)−7.9
=0.5−4.8−7.9
=−12.2
(8) 0.8−4.2+8.3−(−2.8)
=0.8−4.2+8.3+2.8
=11.9−4.2
=7.7
(問7)
(1)\(-\dfrac {1} {2} +\dfrac {2} {3}\)
(2)\(-\dfrac {1} {3} -\dfrac {3} {4}\)
(3)\(\dfrac {5} {18} -\left( -\dfrac {5} {6} \right) \)
(4)\(-\dfrac {11} {12} +\dfrac {9} {8}\)
(5) −0.8 +\(\dfrac {2} {5}\)
(6)\(-\dfrac {5} {6}\) + 0.7
(7)\(-\dfrac {1} {3} -\left( -\dfrac {1} {2} \right)+\dfrac {5} {6}\)
(8)\(-\dfrac {7} {3} +\left\{ \left( \dfrac {3} {4} -\dfrac {5} {6} \right) +2\right\} -\left( -\dfrac {3} {8} \right) \)
(1)\(-\dfrac {1} {2} +\dfrac {2} {3}\)
(2)\(-\dfrac {1} {3} -\dfrac {3} {4}\)
(3)\(\dfrac {5} {18} -\left( -\dfrac {5} {6} \right) \)
(4)\(-\dfrac {11} {12} +\dfrac {9} {8}\)
(5) −0.8 +\(\dfrac {2} {5}\)
(6)\(-\dfrac {5} {6}\) + 0.7
(7)\(-\dfrac {1} {3} -\left( -\dfrac {1} {2} \right)+\dfrac {5} {6}\)
(8)\(-\dfrac {7} {3} +\left\{ \left( \dfrac {3} {4} -\dfrac {5} {6} \right) +2\right\} -\left( -\dfrac {3} {8} \right) \)
(1)\(-\dfrac {1} {2} +\dfrac {2} {3}\)
=\(-\dfrac {3} {6} +\dfrac {4} {6}\)
=\(\dfrac {1} {6}\)
(2)\(-\dfrac {1} {3} -\dfrac {3} {4}\)
=\(-\dfrac {4} {12} -\dfrac {9} {12}\)
=\(-\dfrac {13} {12}\)
(3)\(\dfrac {5} {18} -\left( -\dfrac {5} {6} \right) \)
=\(\dfrac {5} {18} +\dfrac {5} {6}\)
=\(\dfrac {5} {18} +\dfrac {15} {18}\)
=\(\dfrac {20} {18}\)
=\(\dfrac {10} {9}\)
(4)\(-\dfrac {11} {12} +\dfrac {9} {8}\)
=\(-\dfrac {22} {24} +\dfrac {27} {24}\)
=\(\dfrac {5} {24}\)
(5) −0.8 +\(\dfrac {2} {5}\)
=\(-\dfrac {4} {5} +\dfrac {2} {5}\)
=\(-\dfrac {2} {5}\)
(6)\(-\dfrac {5} {6}\) + 0.7
=\(-\dfrac {5} {6} +\dfrac {7} {10}\)
=\(-\dfrac {25} {30} +\dfrac {21} {30}\)
=\(-\dfrac {4} {30}\)
=\(-\dfrac {2} {15}\)
(7)\(-\dfrac {1} {3} -\left( -\dfrac {1} {2} \right)+\dfrac {5} {6}\)
=\(-\dfrac {1} {3} +\dfrac {1} {2} +\dfrac {5} {6}\)
=\(-\dfrac {2} {6} +\dfrac {3} {6} +\dfrac {5} {6}\)
=\(\dfrac {6} {6}\)
= 1
(8)\(-\dfrac {7} {3} +\left\{ \left( \dfrac {3} {4} -\dfrac {5} {6} \right) +2\right\} -\left( -\dfrac {3} {8} \right) \)
=\(-\dfrac {7} {3} +\left( -\dfrac {1} {12} + 2\right) -\left( -\dfrac {3} {8} \right) \)
=\(-\dfrac {7} {3} +\dfrac {23} {12} +\dfrac {3} {8}\)
=\(-\dfrac {56} {24} +\dfrac {46} {24} +\dfrac {9} {24}\)
=\(-\dfrac {1} {24}\)