13 bài tập Đo diện tích – đo thể tích có lời giải

Hướng Dẫn Giải

- \(27{m^2} = 27 \times 100d{m^2} = 2700d{m^2}\);

- \(782d{m^2} = 700d{m^2} + 82d{m^2} = 700:100{m^2} + 82d{m^2}\)

\( = 7{m^2} + 82d{m^2} = 7{m^2}82d{m^2}\).

- \(4000c{m^2} = 4000:100d{m^2} = 40d{m^2}\).

- \(123456c{m^2} = 120000c{m^2} + 3400c{m^2} + 56c{m^2}\)

\( = 120000:10000c{m^2} + 3400:100d{m^2} + 56c{m^2}\)

\( = 12{m^2} + 34d{m^2} + 56c{m^2} = 12{m^2}34d{m^2}56c{m^2}\).

- \(79{m^2}3d{m^2} = 79{m^2} + 3d{m^2} = 79 \times 100d{m^2} + 3d{m^2}\)

\( = 7900d{m^2} + 3d{m^2} = 7903d{m^2}\).

- \(52{m^2}94d{m^2} = 52{m^2} + 94d{m^2} = 52 \times 100d{m^2} + 94d{m^2}\)

\( = 5200d{m^2} + 94d{m^2} = 5294d{m^2}\).

Hướng Dẫn Giải

- \(9{m^2} = ..........d{m^2}\)

\(9{m^2} = 9 \times 100d{m^2} = 900d{m^2}\)

- \(490{m^2} = ..........d{m^2}\)

\(490{m^2} = 490 \times 100d{m^2} = 49000d{m^2}\)

- \(172{\rm{ d}}{{\rm{m}}^2} = ...{\rm{ c}}{{\rm{m}}^2}\)

\(172{\rm{ d}}{{\rm{m}}^2} = 172 \times 100{\rm{ c}}{{\rm{m}}^2} = 17200{\rm{ c}}{{\rm{m}}^2}\).

- \(9657{\rm{d}}{{\rm{m}}^2} = ...{\rm{ }}{{\rm{m}}^2}...{\rm{ d}}{{\rm{m}}^2}\)

\(9657{\rm{ d}}{{\rm{m}}^2} = 9600{\rm{d}}{{\rm{m}}^2} + 57{\rm{d}}{{\rm{m}}^2} = 9600:100{\rm{ }}{{\rm{m}}^2} + 57{\rm{d}}{{\rm{m}}^2} = 96{{\rm{m}}^2} + 57{\rm{d}}{{\rm{m}}^2}\)

\( = 96{{\rm{m}}^2}57{\rm{d}}{{\rm{m}}^2}\)

- \(9{{\rm{m}}^2}3{\rm{d}}{{\rm{m}}^2} = ..........{\rm{d}}{{\rm{m}}^2}\)

\(9{{\rm{m}}^2}3{\rm{d}}{{\rm{m}}^2} = 9{{\rm{m}}^2} + 3{\rm{d}}{{\rm{m}}^2} = 9 \times 100{\rm{d}}{{\rm{m}}^2} + 3{\rm{d}}{{\rm{m}}^2} = 900{\rm{d}}{{\rm{m}}^2} + 3{\rm{d}}{{\rm{m}}^2} = 903{\rm{d}}{{\rm{m}}^2}\)

- \(4{\rm{ }}{{\rm{m}}^2}25{\rm{ d}}{{\rm{m}}^2} = ...{\rm{ c}}{{\rm{m}}^2}\)

\(4{{\rm{m}}^2}25{\rm{d}}{{\rm{m}}^2} = 4{{\rm{m}}^2} + 25{\rm{d}}{{\rm{m}}^2} = 4 \times 10000{\rm{c}}{{\rm{m}}^2} + 25 \times 100{\rm{c}}{{\rm{m}}^2}\)

\( = 40000{\rm{c}}{{\rm{m}}^2} + 2500{\rm{c}}{{\rm{m}}^2} = 42500{\rm{c}}{{\rm{m}}^2}\)

- \(39{\rm{d}}{{\rm{m}}^2}4{\rm{ c}}{{\rm{m}}^2} = ...{\rm{c}}{{\rm{m}}^2}\)

\(39{\rm{d}}{{\rm{m}}^2}4{\rm{c}}{{\rm{m}}^2} = 39{\rm{d}}{{\rm{m}}^2} + 4{\rm{c}}{{\rm{m}}^2} = 39 \times 100{\rm{ c}}{{\rm{m}}^2} + 4{\rm{c}}{{\rm{m}}^2}\)

\( = 3900{\rm{c}}{{\rm{m}}^2} + 4{\rm{c}}{{\rm{m}}^2} = 3904{\rm{c}}{{\rm{m}}^2}\)

- \(1{{\rm{m}}^2}78{\rm{ d}}{{\rm{m}}^2} = ...{\rm{ c}}{{\rm{m}}^2}\)

\(1{{\rm{m}}^2}78{\rm{d}}{{\rm{m}}^2} = 1{{\rm{m}}^2} + 78{\rm{d}}{{\rm{m}}^2} = 1 \times 10000{\rm{c}}{{\rm{m}}^2} + 78 \times 100{\rm{c}}{{\rm{m}}^2}\)

\( = 10000{\rm{c}}{{\rm{m}}^2} + 7800{\rm{c}}{{\rm{m}}^2} = 17800{\rm{c}}{{\rm{m}}^2}\)

Hướng Dẫn Giải

- \(912{\rm{ }}{{\rm{m}}^2} = 91200{\rm{ d}}{{\rm{m}}^2}\)

- \(10{\rm{ k}}{{\rm{m}}^2} = 10000000{\rm{ }}{{\rm{m}}^2}\)

- \(7{\rm{ d}}{{\rm{m}}^2} = 700{\rm{ c}}{{\rm{m}}^2}\)

- \(8{{\rm{m}}^2}79{\rm{d}}{{\rm{m}}^2} = 879{\rm{ d}}{{\rm{m}}^2}\)

- \(2016{\rm{c}}{{\rm{m}}^2} = 20{\rm{ d}}{{\rm{m}}^2}16{\rm{ c}}{{\rm{m}}^2}\)

- \(9{{\rm{m}}^2}9{\rm{d}}{{\rm{m}}^2} = 909{\rm{ d}}{{\rm{m}}^2}\)

- \(7{{\rm{m}}^2}8{\rm{d}}{{\rm{m}}^2} = 708{\rm{ d}}{{\rm{m}}^2}\)

Hướng Dẫn Giải

\(14{\rm{da}}{{\rm{m}}^2} = 14 \times 100{\rm{ }}{{\rm{m}}^2} = 1400{{\rm{m}}^2}\)

\(1700{{\rm{m}}^2} = 1700:100{\rm{ da}}{{\rm{m}}^2} = 17{\rm{da}}{{\rm{m}}^2}\)

\(16{\rm{da}}{{\rm{m}}^2}10{{\rm{m}}^2} = 16{\rm{da}}{{\rm{m}}^2} + 10{{\rm{m}}^2} = 16 \times 100{{\rm{m}}^2} + 10{{\rm{m}}^2} = 1610{{\rm{m}}^2}\)

\(37{\rm{da}}{{\rm{m}}^2}9{{\rm{m}}^2} = 37{\rm{da}}{{\rm{m}}^2} + 9{{\rm{m}}^2} = 37 \times 100{{\rm{m}}^2} + 9{{\rm{m}}^2} = 3709{{\rm{m}}^2}\)

\(1{{\rm{m}}^2} = 1:100{\rm{ da}}{{\rm{m}}^2} = \frac{1}{{100}}{\rm{ da}}{{\rm{m}}^2}({\rm{hay }}0,01{\rm{da}}{{\rm{m}}^2})\)

\(8{\rm{da}}{{\rm{m}}^2} = 8:100{\rm{h}}{{\rm{m}}^2} = \frac{8}{{100}}{\rm{h}}{{\rm{m}}^2}({\rm{hay }}0,08{\rm{h}}{{\rm{m}}^2})\)

\(26{{\rm{m}}^2} = 26:100{\rm{da}}{{\rm{m}}^2} = \frac{{26}}{{100}}{\rm{da}}{{\rm{m}}^2}({\rm{hay }}0,26{\rm{da}}{{\rm{m}}^2})\)

\(42{\rm{da}}{{\rm{m}}^2} = 42:100{\rm{h}}{{\rm{m}}^2} = \frac{{42}}{{100}}{\rm{ h}}{{\rm{m}}^2}({\rm{hay }}0,42{\rm{h}}{{\rm{m}}^2})\)

\(15{{\rm{m}}^2} = 15 \times 10000{\rm{c}}{{\rm{m}}^2} = 150000{\rm{ c}}{{\rm{m}}^2}\)

\(7{\rm{da}}{{\rm{m}}^2} = 7 \times 10000{\rm{d}}{{\rm{m}}^2} = 70000{\rm{d}}{{\rm{m}}^2}\).

Hướng Dẫn Giải

- \(2{\rm{da}}{{\rm{m}}^2}16{{\rm{m}}^2} = 2{\rm{da}}{{\rm{m}}^2} + 16{{\rm{m}}^2} = 2{\rm{da}}{{\rm{m}}^2} + 16:100{\rm{da}}{{\rm{m}}^2}\)

\( = 2{\rm{da}}{{\rm{m}}^2} + 0,16{\rm{da}}{{\rm{m}}^2} = 2,16{\rm{da}}{{\rm{m}}^2}\)

Vậy \(2{\rm{da}}{{\rm{m}}^2}16{{\rm{m}}^2} = 2,16{\rm{da}}{{\rm{m}}^2}\)

Tương tự có:

- \(8{\rm{da}}{{\rm{m}}^2}62{{\rm{m}}^2} = 8,62{\rm{da}}{{\rm{m}}^2}\)

- \(52{\rm{da}}{{\rm{m}}^2}40{{\rm{m}}^2} = 52,4{\rm{da}}{{\rm{m}}^2}\)

- \(46{\rm{da}}{{\rm{m}}^2}5{{\rm{m}}^2} = 46,05{\rm{da}}{{\rm{m}}^2}\)

- \(16{\rm{da}}{{\rm{m}}^2}29{{\rm{m}}^2} = 16,29{\rm{da}}{{\rm{m}}^2}\)

- \(32{\rm{da}}{{\rm{m}}^2}9{{\rm{m}}^2} = 32,09{\rm{da}}{{\rm{m}}^2}\)

- \(3{\rm{k}}{{\rm{m}}^2}4{\rm{c}}{{\rm{m}}^2} = 3{\rm{k}}{{\rm{m}}^2} + 4{\rm{c}}{{\rm{m}}^2} = 3 \times 10000{\rm{da}}{{\rm{m}}^2} + 4:1000000{\rm{da}}{{\rm{m}}^2}\)

\( = 30000{\rm{da}}{{\rm{m}}^2} + 0,000004{\rm{da}}{{\rm{m}}^2} = 30000,000004{\rm{da}}{{\rm{m}}^2}\)

- \(13{\rm{ h}}{{\rm{m}}^2}24{\rm{d}}{{\rm{m}}^2} = 13 \times 100{\rm{da}}{{\rm{m}}^2} + 24:10000{\rm{da}}{{\rm{m}}^2}\)

\( = 1300{\rm{da}}{{\rm{m}}^2} + 0,0024{\rm{da}}{{\rm{m}}^2} = 1300,0024{\rm{da}}{{\rm{m}}^2}\).

Chu vi khu đất của ông Tư là:

\((48 + 25) \times 2 = 146{\rm{ (m)}}\)

Do ông Tư chừa lối đi rộng 2m nên thực tế ông đã thuê rào số mét là:

\(146 - 2 = 144{\rm{ (m)}}\)

Đổi \(144{\rm{ m}} = 1440{\rm{ dm}}\).

Số tiền ông Tư phải trả là:

\(1440 \times 2500 = 3600000{\rm{ (d?ng)}}\)

Đáp Số: 3 600 000 (đồng)